mb/google/skyrim: Do not pass recovery APCB

If recovery APCB is not passed, amdfwtool will build amdfw*.rom with
AMD_BIOS_APCB_BK entry pointing to the same offset as AMD_BIOS_APCB
entry. This will help to save 40 KiB flash space in each FW slot. On
ChromeOS, this means saving ~120 KiB flash space.

BUG=b:240696002
TEST=Build and boot to OS in Skyrim.

Change-Id: Ib3bbc1eededae20b2cd48f514722a207c46536a0
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73662
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/skyrim/Makefile.inc b/src/mainboard/google/skyrim/Makefile.inc
index c1d1108..5a44d8b 100644
--- a/src/mainboard/google/skyrim/Makefile.inc
+++ b/src/mainboard/google/skyrim/Makefile.inc
@@ -29,7 +29,6 @@
 LIB_SPD_DEPS = $(SPD_SOURCES)
 
 APCB_SOURCES = $(obj)/$(APCB_NAME).gen
-APCB_SOURCES_RECOVERY = $(obj)/$(APCB_NAME).gen
 
 $(obj)/$(APCB_NAME).gen: $(SPD_SOURCES) \
 			$(APCB_V3_EDIT_TOOL) \