Tegra: memmap the actual memory available for BL31

On Tegra SoCs, the TZDRAM contains the BL31 and BL32 images. This patch
uses only the actual memory available for BL31 instead of mapping the
entire TZDRAM.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -195,7 +195,7 @@ void bl31_plat_arch_setup(void)
 {
 	unsigned long bl31_base_pa = tegra_bl31_phys_base;
 	unsigned long total_base = bl31_base_pa;
-	unsigned long total_size = TZDRAM_END - BL31_RO_BASE;
+	unsigned long total_size = BL32_BASE - BL31_RO_BASE;
 	unsigned long ro_start = bl31_base_pa;
 	unsigned long ro_size = BL31_RO_LIMIT - BL31_RO_BASE;
 	const mmap_region_t *plat_mmio_map = NULL;