MLK-12483-1 common: Fix fdt command systemsetup issue

The fdt command "fdt systemsetup" can't work because the do_fdt check the
start char 's' for command "fdt set". So the fdt systemsetup will also go into
the "fdt set" in fault. Fix this problem by checking the whole word "set" for
"fdt set" command.

Signed-off-by: Ye Li <ye.li@nxp.com>

cmd/fdt.c

@@ -244,7 +244,7 @@ static int do_fdt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	/*
 	 * Set the value of a property in the working_fdt.
 	 */
-	} else if (argv[1][0] == 's') {
+	} else if (strncmp(argv[1], "set", 3) == 0) {
 		char *pathp;		/* path */
 		char *prop;		/* property */
 		int  nodeoffset;	/* node offset from libfdt */