x86: copy config and patches from 5.10 to 5.15

So the upcoming changes needed for 5.15 can be reviewed easily.
Removing following patches backported from 5.15:

 * 101-v5.15-mfd-lpc_ich-Enable-GPIO-driver-for-DH89xxCC.patch
 * 102-v5.15-platform-x86-add-meraki-mx100-platform-driver.patch

Removed upstreamed patch `300-pcengines_apu1_led.patch` in commit
1b40faf7e4ab ("leds: apu: extend support for PC Engines APU1 with newer
firmware")

Signed-off-by: Petr Štetiar <ynezz@true.cz>