arch/arm64: Pass cbmem_top to ramstage via calling argument

This solution is very generic and can in principle be implemented on
all arch/soc. Currently the old infrastructure to pass on information
from romstage to ramstage is left in place and will be removed in a
follow-up commit.

Nvidia Tegra will be handled in a separate patch because it has a
custom ramstage entry.

Instead trying to figure out which files can be removed from stages
and which cbmem_top implementations need with preprocessor, rename all
cbmem_top implementation to cbmem_top_romstage.

Mechanisms set in place to pass on information from rom- to ram-stage
will be replaced in a followup commit.

Change-Id: I86cdc5c2fac76797732a3a3398f50c4d1ff6647a
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36275
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/soc/mediatek/mt8173/Makefile.inc

@@ -64,7 +64,7 @@ romstage-y += ../common/rtc.c rtc.c
 
 ################################################################################
 
-ramstage-y += ../common/cbmem.c emi.c
+ramstage-y += emi.c
 ramstage-y += ../common/spi.c spi.c
 ramstage-$(CONFIG_SPI_FLASH) += flash_controller.c
 ramstage-y += soc.c ../common/mtcmos.c

src/soc/mediatek/mt8183/Makefile.inc

@@ -45,7 +45,7 @@ romstage-y += ../common/uart.c
 romstage-y += ../common/wdt.c
 
 ramstage-y += auxadc.c
-ramstage-y += ../common/cbmem.c emi.c
+ramstage-y += emi.c
 ramstage-y += ../common/ddp.c ddp.c
 ramstage-y += ../common/dsi.c dsi.c
 ramstage-y += ../common/gpio.c gpio.c