85xx: Fix compile warning in mpc8536ds.c

mpc8536ds.c: In function 'is_sata_supported':
mpc8536ds.c:615: warning: unused variable 'devdisr'

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/board/freescale/mpc8536ds/mpc8536ds.c b/board/freescale/mpc8536ds/mpc8536ds.c
index ce77bb9..f357826 100644
--- a/board/freescale/mpc8536ds/mpc8536ds.c
+++ b/board/freescale/mpc8536ds/mpc8536ds.c
@@ -612,7 +612,6 @@
 int is_sata_supported(void)
 {
 	volatile ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
-	uint devdisr = gur->devdisr;
 	uint sdrs2_io_sel =
 		(gur->pordevsr & MPC85xx_PORDEVSR_SRDS2_IO_SEL) >> 27;
 	if (sdrs2_io_sel & 0x04)