ib-drm-gpio-pdx86-rtc-wdt for v5.12-1

First part of Intel MID outdated platforms removal.

The following is an automated git shortlog grouped by driver:

drm/gma500:
 -  Get rid of duplicate NULL checks
 -  Convert to use new SCU IPC API

gpio:
 -  msic: Remove driver for deprecated platform
 -  intel-mid: Remove driver for deprecated platform

intel_mid_powerbtn:
 -  Remove driver for deprecated platform

intel_mid_thermal:
 -  Remove driver for deprecated platform

intel_scu_wdt:
 -  Get rid of custom x86 model comparison
 -  Drop SCU notification
 -  Move driver from arch/x86

rtc:
 -  mrst: Remove driver for deprecated platform

watchdog:
 -  intel-mid_wdt: Postpone IRQ handler registration till SCU is ready
 -  intel_scu_watchdog: Remove driver for deprecated platform