configs: ti: Add environment support commands for FIT loading

Some parts of these commands can be reused, add them to common files.

Signed-off-by: Andrew F. Davis <afd@ti.com>
diff --git a/include/configs/am65x_evm.h b/include/configs/am65x_evm.h
index 6072e4a..0249a20 100644
--- a/include/configs/am65x_evm.h
+++ b/include/configs/am65x_evm.h
@@ -94,11 +94,14 @@
 		"done;\0"						\
 	"get_kern_mmc=load mmc ${bootpart} ${loadaddr} "		\
 		"${bootdir}/${name_kern}\0"				\
+	"get_fit_mmc=load mmc ${bootpart} ${addr_fit} "			\
+		"${bootdir}/${name_fit}\0"				\
 	"partitions=" PARTS_DEFAULT
 
 /* Incorporate settings into the U-Boot environment */
 #define CONFIG_EXTRA_ENV_SETTINGS					\
 	DEFAULT_MMC_TI_ARGS						\
+	DEFAULT_FIT_TI_ARGS						\
 	EXTRA_ENV_AM65X_BOARD_SETTINGS					\
 	EXTRA_ENV_AM65X_BOARD_SETTINGS_MMC
 
diff --git a/include/configs/ti_armv7_common.h b/include/configs/ti_armv7_common.h
index 2058f8d..2de6bc2 100644
--- a/include/configs/ti_armv7_common.h
+++ b/include/configs/ti_armv7_common.h
@@ -55,7 +55,13 @@
 	"addr_fit=0x90000000\0" \
 	"name_fit=fitImage\0" \
 	"update_to_fit=setenv loadaddr ${addr_fit}; setenv bootfile ${name_fit}\0" \
-	"loadfit=run args_mmc; bootm ${loadaddr}#${fdtfile};\0" \
+	"get_overlaystring=" \
+		"for overlay in $overlay_files;" \
+		"do;" \
+		"setenv overlaystring ${overlaystring}'#'${overlay};" \
+		"done;\0" \
+	"run_fit=bootm ${loadaddr}#${fdtfile}${overlaystring}\0" \
+	"loadfit=run args_mmc; run run_fit;\0" \
 
 /*
  * DDR information.  If the CONFIG_NR_DRAM_BANKS is not defined,