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/gm45/Makefile.inc b/src/northbridge/intel/gm45/Makefile.inc
index b59a7c3..0ab1c94 100644
--- a/src/northbridge/intel/gm45/Makefile.inc
+++ b/src/northbridge/intel/gm45/Makefile.inc
@@ -25,18 +25,18 @@
 romstage-y += thermal.c
 romstage-y += igd.c
 romstage-y += pm.c
-romstage-y += ram_calc.c
+romstage-y += memmap.c
 romstage-y += iommu.c
 romstage-y += romstage.c
 
 ramstage-y += acpi.c
 
-ramstage-y += ram_calc.c
+ramstage-y += memmap.c
 ramstage-y += northbridge.c
 ramstage-y += gma.c
 
 smm-y += ../../../cpu/x86/lapic/apic_timer.c
 
-postcar-y += ram_calc.c
+postcar-y += memmap.c
 
 endif