mx6memcal: spl: Disambiguate the error message

Currently mmdc_do_dqs_calibration() and mmdc_do_write_level_calibration()
show the same error message, which is confusing for debugging.

Disambiguate the mmdc_do_dqs_calibration() error message.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>

board/freescale/mx6memcal/spl.c

@@ -446,7 +446,7 @@ void board_init_f(ulong dummy)
 	} else {
 		errs = mmdc_do_dqs_calibration(&sysinfo);
 		if (errs) {
-			printf("error %d from write level calibration\n", errs);
+			printf("error %d from dqs calibration\n", errs);
 		} else {
 			printf("completed successfully\n");
 			mmdc_read_calibration(&sysinfo, &calibration);