Fix conditional compilation of mpx8xxx_spi driver

This driver should only compile if CONFIG_MPC8XXX_SPI is set

Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/include/configs/MPC8349EMDS.h b/include/configs/MPC8349EMDS.h
index 07f2f30..bb90c2d 100644
--- a/include/configs/MPC8349EMDS.h
+++ b/include/configs/MPC8349EMDS.h
@@ -356,6 +356,7 @@
 #define CFG_I2C2_OFFSET		0x3100
 
 /* SPI */
+#define CONFIG_MPC8XXX_SPI
 #define CONFIG_HARD_SPI			/* SPI with hardware support */
 #undef CONFIG_SOFT_SPI			/* SPI bit-banged */