imx8qxp_mek: drop warning due to unused variable

Signed-off-by: Stefano Babic <sbabic@denx.de>
diff --git a/board/freescale/imx8qxp_mek/spl.c b/board/freescale/imx8qxp_mek/spl.c
index 51f3238..cb4006e 100644
--- a/board/freescale/imx8qxp_mek/spl.c
+++ b/board/freescale/imx8qxp_mek/spl.c
@@ -18,7 +18,6 @@
 void spl_board_init(void)
 {
 	struct udevice *dev;
-	int offset;
 
 	uclass_find_first_device(UCLASS_MISC, &dev);