configs: k2*_evm: Update fdt file names

Now that all Keystone2 dts file names are changed in Linux kernel, reflect the
same in evn variables inorder to find the right dtb file.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/include/configs/k2l_evm.h b/include/configs/k2l_evm.h
index f366e67..2322ab2 100644
--- a/include/configs/k2l_evm.h
+++ b/include/configs/k2l_evm.h
@@ -21,7 +21,7 @@
 	"addr_mon=0x0c140000\0"						\
 	"args_ubi=setenv bootargs ${bootargs} rootfstype=ubifs "	\
 	"root=ubi0:rootfs rootflags=sync rw ubi.mtd=ubifs,4096\0"	\
-	"name_fdt=k2l-evm.dtb\0"					\
+	"name_fdt=keystone-k2l-evm.dtb\0"				\
 	"name_mon=skern-k2l.bin\0"					\
 	"name_ubi=k2l-evm-ubifs.ubi\0"					\
 	"name_uboot=u-boot-spi-k2l-evm.gph\0"				\