The filesystems are now mounted in the same way the sysmobts2100
build does it.
This fixes the failing checkflash systemd service on the oc2g.
Related: SYS#4493
This is needed for osmo-bts to properly transmit on OC2g because it
contains calibration values for the amplifier. Without the transmit
power will be really low (probably just what leaks through the amp).
I think the last device we sold was in 2011 and I am not aware
if anyone has used it for the last couple of years. Remove it
to lower the complexity of the builds.