northbridge/intel: Rename ram_calc.c to memmap.c

Use a name consistent with the more recent soc/intel.

Change-Id: Ie69583f28f384eb49517203e1c3867f27e6272de
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34699
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/northbridge/intel/sandybridge/Makefile.inc b/src/northbridge/intel/sandybridge/Makefile.inc
index 8a0b67b..77d1fdb 100644
--- a/src/northbridge/intel/sandybridge/Makefile.inc
+++ b/src/northbridge/intel/sandybridge/Makefile.inc
@@ -15,14 +15,14 @@
 
 ifeq ($(CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE),y)
 
-ramstage-y += ram_calc.c
+ramstage-y += memmap.c
 ramstage-y += northbridge.c
 ramstage-y += pcie.c
 ramstage-y += gma.c
 
 ramstage-y += acpi.c
 
-romstage-y += ram_calc.c
+romstage-y += memmap.c
 
 ramstage-y += common.c
 romstage-y += common.c
@@ -48,6 +48,6 @@
 
 smm-y += finalize.c
 
-postcar-y += ram_calc.c
+postcar-y += memmap.c
 
 endif