board: lx2160a: use default scan_dev_for_boot

Default environment variable is more complete. Also scans for efi
binaries for example.

Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>

include/configs/lx2160a_common.h

@@ -246,12 +246,6 @@ unsigned long get_board_ddr_clk(void);
 				"run scan_dev_for_boot; "	\
 			"fi; "					\
 		"done\0"					\
-	"scan_dev_for_boot="					\
-		"echo Scanning ${devtype} "			\
-			"${devnum}:${distro_bootpart}...; "	\
-		"for prefix in ${boot_prefixes}; do "		\
-			"run scan_dev_for_scripts; "		\
-		"done;\0"					\
 	"boot_a_script="					\
 		"load ${devtype} ${devnum}:${distro_bootpart} "	\
 			"${scriptaddr} ${prefix}${script}; "	\