include: configs: omap5: Add support for FDT overlay

As AM57x uses overlays for display and camera interfaces, add support to
load DT overlay files to MMC boot.

Signed-off-by: Sinthu Raja <sinthu.raja@ti.com>
Signed-off-by: Anurag Dutta <a-dutta@ti.com>

include/configs/ti_omap5_common.h

@@ -239,6 +239,16 @@
 		"if test $fdtfile = undefined; then " \
 			"echo WARNING: Could not determine device tree to use; fi; \0"
 
+#define GET_OVERLAY_MMC_TI_ARGS \
+	"get_overlay_mmc=" \
+		"fdt address ${fdtaddr};" \
+		"fdt resize 0x100000;" \
+		"for overlay in $name_overlays;" \
+		"do;" \
+			"load mmc ${bootpart} ${dtboaddr} ${bootdir}/dtb/${overlay} &&" \
+			"fdt apply ${dtboaddr};" \
+		"done;\0" \
+
 #define BOOT_TARGET_DEVICES(func) \
 	func(TI_MMC, ti_mmc, na) \
 	func(MMC, mmc, 0) \
@@ -269,6 +279,7 @@
 	"get_fit_config=setenv name_fit_config ${fdtfile}\0" \
 	DEFAULT_COMMON_BOOT_TI_ARGS \
 	DEFAULT_FDT_TI_ARGS \
+	GET_OVERLAY_MMC_TI_ARGS \
 	DFUARGS \
 	NETARGS \
 	NANDARGS \

include/env/ti/mmc.h

@@ -44,6 +44,7 @@
 	"mmcloados=" \
 		"if test ${boot_fdt} = yes || test ${boot_fdt} = try; then " \
 			"if run loadfdt; then " \
+				"run get_overlay_mmc;" \
 				"bootz ${loadaddr} - ${fdtaddr}; " \
 			"else " \
 				"if test ${boot_fdt} = try; then " \