[MTD] [NAND] pxa3xx_nand: allow building as module

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 68ae144..4e70739 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -334,7 +334,7 @@
 endchoice
 
 config MTD_NAND_PXA3xx
-	bool "Support for NAND flash devices on PXA3xx"
+	tristate "Support for NAND flash devices on PXA3xx"
 	depends on MTD_NAND && PXA3xx
 	help
 	  This enables the driver for the NAND flash device found on