ACPI S3: Drop ACPI_HUGE_LOWMEM_BACKUP

ACPI S3 resume path can only modify low memory where
the non-relocatable ramstage resides, there is no need
to maintain a bigger backup copy.

Change-Id: Ifae41b51b359010ec02269c674936a87bd15623b
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/15476
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/Kconfig

@@ -485,12 +485,6 @@ config HAVE_ACPI_RESUME
 	bool
 	default n
 
-config ACPI_HUGE_LOWMEM_BACKUP
-	bool
-	default n
-	help
-	  On S3 resume path, backup low memory from RAMBASE..RAMTOP in CBMEM.
-
 config RESUME_PATH_SAME_AS_BOOT
 	bool
 	default y if ARCH_X86