environment: ti: mmc.h: Make the finduuid generic for usage across different device types

Make finduuid generic by making it dependent on the boot variable. For
example, this can now be used for finding the uuid of partitions in usb
device too.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
diff --git a/include/environment/ti/mmc.h b/include/environment/ti/mmc.h
index b86c8dc..769ea9d 100644
--- a/include/environment/ti/mmc.h
+++ b/include/environment/ti/mmc.h
@@ -11,7 +11,7 @@
 #define DEFAULT_MMC_TI_ARGS \
 	"mmcdev=0\0" \
 	"mmcrootfstype=ext4 rootwait\0" \
-	"finduuid=part uuid mmc ${bootpart} uuid\0" \
+	"finduuid=part uuid ${boot} ${bootpart} uuid\0" \
 	"args_mmc=run finduuid;setenv bootargs console=${console} " \
 		"${optargs} " \
 		"root=PARTUUID=${uuid} rw " \