Revert "Enable qcom usb serial driver"

This is no longer needed as ril stack from E980 uses /dev/ks_bridge instead
This reverts commit 7d9b4cb7e91ba3e568238d8f99ba84d83871ef66.
Make sure that RTC is writable in the gk board

This is needed for AOSP to set the correct HWCLOCK.
If one would now reboot in airplane mode, time should still be
set correctly and not reset to sometime in 1970.

Change-Id: I4ee91c466593c76049f3999657406b75ede27720
Do not need it when we use LG's ril