libpayload arm64: Allocate framebuffer range

Allocate noncacheable memory for frame buffer and save base
address to sys_libinfo.

BRANCH=none
BUG=chrome-os-partner:31936
TEST=build and test on ryu

Change-Id: I19a8079616376dc7c1a8ecdbd7499c2553b8c6c3
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: cebb5650167264902548339bb1a2b428f3b7f4ed
Original-Change-Id: I7bfbfefb92001632ce3d572a50e46188795c4ab8
Original-Signed-off-by: Jimmy Zhang <jimmzhang@nvidia.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/226404
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8796
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/include/arm64/arch/mmu.h

@@ -181,6 +181,8 @@ extern char _start[], _end[];
 #define DMA_DEFAULT_SIZE           (0x20 * GRANULE_SIZE)
 #define TTB_DEFAULT_SIZE           0x100000
 
+#define MB_SIZE			   (1UL << 20)
+
 /* Initialize the MMU TTB tables using the mmu_ranges */
 uint64_t mmu_init(struct mmu_ranges *mmu_ranges);