cbmem_top_chipset: Change the return value to uintptr_t

Get rid of a lot of casts.

Change-Id: I93645ef5dd270905ce421e68e342aff4c331eae6
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69078
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>
diff --git a/src/soc/nvidia/tegra124/cbmem.c b/src/soc/nvidia/tegra124/cbmem.c
index 3f59f06..287ef629 100644
--- a/src/soc/nvidia/tegra124/cbmem.c
+++ b/src/soc/nvidia/tegra124/cbmem.c
@@ -1,10 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <cbmem.h>
+#include <commonlib/bsd/helpers.h>
 #include <soc/display.h>
 #include <soc/sdram.h>
 
-void *cbmem_top_chipset(void)
+uintptr_t cbmem_top_chipset(void)
 {
-	return (void *)((sdram_max_addressable_mb() - FB_SIZE_MB) << 20UL);
+	return (sdram_max_addressable_mb() - FB_SIZE_MB) * MiB;
 }