ACPI: Remove Kconfig COMMON_FADT

Also remove default mb/*/fadt.c from Makefiles.

Change-Id: I6a2839c524f8311ec9a382a84066afc7d579eaca
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41948
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/quark/Kconfig

@@ -26,7 +26,6 @@ config CPU_SPECIFIC_OPTIONS
 	select UNCOMPRESSED_RAMSTAGE
 	select USE_MARCH_586
 	select NO_SMM
-	select COMMON_FADT
 
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 # Debug serial output