Tegra: Exclude coherent memory region from memory map

This patch sets the 'USE_COHERENT_MEM' flag to '0', so that the
coherent memory region will not be included in the memory map.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -196,13 +196,9 @@ void bl31_plat_arch_setup(void)
 	unsigned long total_size = TZDRAM_END - BL31_RO_BASE;
 	unsigned long ro_start = bl31_base_pa;
 	unsigned long ro_size = BL31_RO_LIMIT - BL31_RO_BASE;
-	unsigned long coh_start = 0;
-	unsigned long coh_size = 0;
 	const mmap_region_t *plat_mmio_map = NULL;
-
 #if USE_COHERENT_MEM
-	coh_start = total_base + (BL31_COHERENT_RAM_BASE - BL31_RO_BASE);
-	coh_size = BL31_COHERENT_RAM_LIMIT - BL31_COHERENT_RAM_BASE;
+	unsigned long coh_start, coh_size;
 #endif
 
 	/* add memory regions */
@@ -212,7 +208,11 @@ void bl31_plat_arch_setup(void)
 	mmap_add_region(ro_start, ro_start,
 			ro_size,
 			MT_MEMORY | MT_RO | MT_SECURE);
+
 #if USE_COHERENT_MEM
+	coh_start = total_base + (BL31_COHERENT_RAM_BASE - BL31_RO_BASE);
+	coh_size = BL31_COHERENT_RAM_LIMIT - BL31_COHERENT_RAM_BASE;
+
 	mmap_add_region(coh_start, coh_start,
 			coh_size,
 			MT_DEVICE | MT_RW | MT_SECURE);

plat/nvidia/tegra/common/tegra_common.mk

@@ -34,6 +34,8 @@ $(eval $(call add_define,CRASH_REPORTING))
 ASM_ASSERTION		:=	1
 $(eval $(call add_define,ASM_ASSERTION))
 
+USE_COHERENT_MEM	:=	0
+
 PLAT_INCLUDES		:=	-Iplat/nvidia/tegra/include/drivers \
 				-Iplat/nvidia/tegra/include \
 				-Iplat/nvidia/tegra/include/${TARGET_SOC}