Tegra: fix the NS DRAM address calculation logic

This patch fixes the logic used to calculate the end of NS memory
aperture. The functions allows zero sized NS apertures as that is
a valid requirement for some use cases. e.g. VPR resize.

Change-Id: Ie966e0ea2f9c6888d21c38e734003704094b3720
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -381,13 +381,12 @@ void bl31_plat_arch_setup(void)
  ******************************************************************************/
 int bl31_check_ns_address(uint64_t base, uint64_t size_in_bytes)
 {
-	uint64_t end = base + size_in_bytes - 1;
+	uint64_t end = base + size_in_bytes;
 
 	/*
 	 * Check if the NS DRAM address is valid
 	 */
-	if ((base < TEGRA_DRAM_BASE) || (end > TEGRA_DRAM_END) ||
-	    (base >= end)) {
+	if ((base < TEGRA_DRAM_BASE) || (end > TEGRA_DRAM_END)) {
 		ERROR("NS address is out-of-bounds!\n");
 		return -EFAULT;
 	}