Tegra: fix logic to clear videomem regions

The previous logic in the memctrl driver was not catering to cases
where the new memory region lied inside the older region. This patch
fixes the if/elseif/elseif logic in the driver to take care of this
case.

Reported by: Vikram Kanigiri <vikram.kanigiri@arm.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/drivers/memctrl/memctrl.c

@@ -118,6 +118,7 @@ void tegra_memctrl_videomem_setup(uint64_t phys_base, uint32_t size_in_bytes)
 	uintptr_t vmem_end_old = video_mem_base + (video_mem_size << 20);
 	uintptr_t vmem_end_new = phys_base + size_in_bytes;
 	uint32_t regval;
+	uint64_t size;
 
 	/*
 	 * The GPU is the user of the Video Memory region. In order to
@@ -153,12 +154,18 @@ void tegra_memctrl_videomem_setup(uint64_t phys_base, uint32_t size_in_bytes)
 	INFO("Cleaning previous Video Memory Carveout\n");
 
 	disable_mmu_el3();
-	if (phys_base > vmem_end_old || video_mem_base > vmem_end_new)
+	if (phys_base > vmem_end_old || video_mem_base > vmem_end_new) {
 		zeromem16((void *)video_mem_base, video_mem_size << 20);
-	else if (video_mem_base < phys_base)
-		zeromem16((void *)video_mem_base, phys_base - video_mem_base);
-	else if (vmem_end_old > vmem_end_new)
-		zeromem16((void *)vmem_end_new, vmem_end_old - vmem_end_new);
+	} else {
+		if (video_mem_base < phys_base) {
+			size = phys_base - video_mem_base;
+			zeromem16((void *)video_mem_base, size);
+		}
+		if (vmem_end_old > vmem_end_new) {
+			size = vmem_end_old - vmem_end_new;
+			zeromem16((void *)vmem_end_new, size);
+		}
+	}
 	enable_mmu_el3(0);
 
 done: