CBMEM: Do not use get_top_of_ram() with DYNAMIC_CBMEM

The name was always obscure and confusing. Instead define cbmem_top()
directly in the chipset code for x86 like on ARMs.

TODO: Check TSEG alignment, it used for MTRR programming.

Change-Id: Ibbe5f05ab9c7d87d09caa673766cd17d192cd045
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7888
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>
diff --git a/src/northbridge/intel/i945/ram_calc.c b/src/northbridge/intel/i945/ram_calc.c
index d09b2e1..4b7d895 100644
--- a/src/northbridge/intel/i945/ram_calc.c
+++ b/src/northbridge/intel/i945/ram_calc.c
@@ -24,9 +24,9 @@
 #include <cbmem.h>
 #include "i945.h"
 
-unsigned long get_top_of_ram(void)
+static uintptr_t smm_region_start(void)
 {
-	u32 tom;
+	uintptr_t tom;
 
 	if (pci_read_config8(PCI_DEV(0, 0x0, 0), DEVEN) & (DEVEN_D2F0 | DEVEN_D2F1)) {
 		/* IGD enabled, get top of Memory from BSM register */
@@ -53,5 +53,10 @@
 		/* TSEG either disabled or invalid */
 		break;
 	}
-	return (unsigned long) tom;
+	return tom;
+}
+
+void *cbmem_top(void)
+{
+	return (void *) smm_region_start();
 }