ti_omap5_common: Add right dtb file for AM572x-IDK

Add proper dtb file name for AM572x-IDK in env.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

include/configs/ti_omap5_common.h

@@ -104,6 +104,8 @@
 			"setenv fdtfile dra72-evm.dtb; fi;" \
 		"if test $board_name = beagle_x15; then " \
 			"setenv fdtfile am57xx-beagle-x15.dtb; fi;" \
+		"if test $board_name = am572x_idk; then " \
+			"setenv fdtfile am572x-idk.dtb; fi;" \
 		"if test $board_name = am57xx_evm; then " \
 			"setenv fdtfile am57xx-beagle-x15.dtb; fi;" \
 		"if test $fdtfile = undefined; then " \