ARM: qemu-arm: Bump RAM size in AArch64 MMU table

Now that PCI devices work with highmem-enabled QEMU emulation, bump up
the RAM size in the MMU tables to gain access to the full 255 GB of RAM
potential instead of the puny 3 GB.
Signed-off-by: NTuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: NSimon Glass <sjg@chromium.org>

board/emulation/qemu-arm/qemu-arm.c

@@ -28,7 +28,7 @@ static struct mm_region qemu_arm64_mem_map[] = {
 		/* RAM */
 		.virt = 0x40000000UL,
 		.phys = 0x40000000UL,
-		.size = 0xc0000000UL,
+		.size = 255UL * SZ_1G,
 		.attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
 			 PTE_BLOCK_INNER_SHARE
 	}, {