[ARM] pxa/colibri: add NAND config for Colibri PXA3xx boards

NAND feature will be enabled when the appropriate config option is set.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/arch/arm/mach-pxa/include/mach/colibri.h b/arch/arm/mach-pxa/include/mach/colibri.h
index a88d7ca..811743c 100644
--- a/arch/arm/mach-pxa/include/mach/colibri.h
+++ b/arch/arm/mach-pxa/include/mach/colibri.h
@@ -23,6 +23,12 @@
 extern void colibri_pxa3xx_init_eth(struct ax_plat_data *plat_data);
 #endif
 
+#if defined(CONFIG_MTD_NAND_PXA3xx) || defined(CONFIG_MTD_NAND_PXA3xx_MODULE)
+extern void colibri_pxa3xx_init_nand(void);
+#else
+static inline void colibri_pxa3xx_init_nand(void) {}
+#endif
+
 /* physical memory regions */
 #define COLIBRI_SDRAM_BASE	0xa0000000      /* SDRAM region */