udeb: Add fb-modules and include drm and drm_kms_helper on most architecures

The previous version failed to build on alpha:

debian/virtio-modules-4.19.0-3-alpha-generic-di lib/modules/4.19.0-3-alpha-generic/kernel/drivers/i2c/i2c-core.ko
debian/i2c-modules-4.19.0-3-alpha-generic-di lib/modules/4.19.0-3-alpha-generic/kernel/drivers/i2c/i2c-core.ko

and sparc64:

debian/virtio-modules-4.19.0-3-sparc64-di lib/modules/4.19.0-3-sparc64/kernel/drivers/i2c/i2c-core.ko
debian/nic-modules-4.19.0-3-sparc64-di lib/modules/4.19.0-3-sparc64/kernel/drivers/i2c/i2c-core.ko

sparc64 was missing a i2c-modules package, but adding that just gets
it to the same state as alpha.  On both architectures drm_kms_helper
is included in the virtio-modules package as a dependency of
virtio-gpu, and then i2c-core is included as a dependency of
drm_kms_helper.

I don't think it makes sense to make virtio-modules directly depend on
i2c-modules.  (In fact I think virtio-modules was a mistake entirely.)
Instead, for all configurations that enable both DRM and virtio:

1. Add an fb-modules package if it doesn't already exist
2. Include drm and drm_kms_helper in it

debian/changelog

@@ -6,6 +6,8 @@ linux (4.19.20-2) UNRELEASED; urgency=medium
   * udeb: Make nic-wireless-modules depend on mmc-core-modules, not mmc-modules
   * [powerpc*] udeb: Add i2c-modules, mmc-core-modules, nic-wireless-modules
   * [arm64,armhf] udeb: Add mmc-core-modules to Provides of kernel-image
+  * udeb: Add fb-modules and include drm and drm_kms_helper on most
+    architecures
 
  -- Ben Hutchings <ben@decadent.org.uk>  Tue, 12 Feb 2019 12:49:10 +0000
 

debian/installer/modules/alpha-generic/fb-modules

@@ -0,0 +1 @@
+#include <fb-modules>

debian/installer/modules/amd64/fb-modules

@@ -1,2 +1,4 @@
+#include <fb-modules>
+
 vesafb ?
 vga16fb

debian/installer/modules/arm64/fb-modules

@@ -1,2 +1,4 @@
+#include <fb-modules>
+
 ast
 tegra-drm

debian/installer/modules/armhf-armmp/fb-modules

@@ -1,3 +1,5 @@
+#include <fb-modules>
+
 imxdrm
 dw_hdmi-imx
 tegra-drm

debian/installer/modules/fb-modules

@@ -0,0 +1,5 @@
+# We don't include all DRM drivers here as on many platforms we can
+# call system firmware to get hold of a simple framebuffer
+
+drm
+drm_kms_helper

debian/installer/modules/hppa-parisc64-smp/fb-modules

@@ -1,6 +1,4 @@
-drm ?
-drm_kms_helper ?
+#include <fb-modules>
+
 radeon ?
 ttm ?
-
-

debian/installer/modules/i386/fb-modules

@@ -1,3 +1,5 @@
+#include <fb-modules>
+
 lxfb ?
 vesafb ?
 vga16fb

debian/installer/modules/mips-4kc-malta/fb-modules

@@ -0,0 +1 @@
+#include <fb-modules>

debian/installer/modules/mipsel-loongson-3/fb-modules

@@ -1,3 +1,5 @@
+#include <fb-modules>
+
 radeon
 ast
 sm750fb

debian/installer/modules/powerpc-powerpc64/fb-modules

@@ -0,0 +1,2 @@
+# We *don't* want the extra modules listed in powerpc/fb-modules
+#include <fb-modules>

debian/installer/modules/powerpc/fb-modules

@@ -1,3 +1,5 @@
+#include <fb-modules>
+
 # 32-bit PowerMacs mostly have either ATI Rage 128 or Radeon graphics
 # chips for which the offb driver doesn't work properly.  aty128fb is
 # currently built-in but that could plausibly change in future.

debian/installer/modules/ppc64el/fb-modules

@@ -0,0 +1 @@
+#include <fb-modules>

debian/installer/modules/riscv64/fb-modules

@@ -0,0 +1 @@
+#include <fb-modules>

debian/installer/modules/sparc64/fb-modules

@@ -0,0 +1 @@
+#include <fb-modules>