Enable FB_SM750 and DRM_AST for Loongson-3

Some new Loongson servers are using Aspeed BMC, which has an GPU.
Some other Loongson servers are using SM750 GPU instead of AMD's.

Since MIPS doesn't have a generic display driver like VESA, we need
to install sm750fb and (drm_)ast into Loongson's fb-moduels udeb package.

(cherry picked from commit 6fbe9f4e363b32a70adf391e6d74ae21c52f16b6)

debian/changelog

@@ -19,6 +19,10 @@ linux (4.19.13-2) UNRELEASED; urgency=medium
   [ Michal Simek ]
   * [arm64] Enable Xilinx ZynqMP SoC and drivers
 
+  [ YunQiang Su ]
+  * [mipsel, mips64el] Enable DRM_AST and FB_SM750 for loongson-3
+    install ast and sm750fb to loongson-3's fb-modules
+
  -- John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>  Sun, 30 Dec 2018 10:30:57 +0100
 
 linux (4.19.13-1) unstable; urgency=medium

debian/config/kernelarch-mips/config.loongson-3

@@ -37,6 +37,11 @@ CONFIG_CPU_IDLE=y
 CONFIG_DRM=m
 CONFIG_DRM_RADEON=m
 
+##
+## file: drivers/gpu/drm/ast/Kconfig
+##
+CONFIG_DRM_AST=m
+
 ##
 ## file: drivers/i2c/Kconfig
 ##
@@ -78,6 +83,11 @@ CONFIG_REGULATOR=y
 ##
 CONFIG_RTC_DRV_CMOS=y
 
+##
+## file: drivers/staging/sm750fb/Kconfig
+##
+CONFIG_FB_SM750=m
+
 ##
 ## file: drivers/tty/serial/8250/Kconfig
 ##

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

@@ -1 +1,3 @@
 radeon
+ast
+sm750fb