mtd: uclinux: do not allow to be built as a module

There isn't any benefit to building the uClinux MTD map as a module as the
rootfs it requires in order to actually be usable is appended to the
kernel image, not the module.  No known system builds it this way either,
so change the option to "bool".

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Paul Mundt <lethal@linux-sh.org>
CC: Greg Ungerer <gerg@uclinux.org>
CC: uclinux-dev@uclinux.org
CC: linux-mtd@lists.infradead.org
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/maps/Kconfig

@@ -492,7 +492,7 @@ config MTD_BFIN_ASYNC
 	  If compiled as a module, it will be called bfin-async-flash.
 
 config MTD_UCLINUX
-	tristate "Generic uClinux RAM/ROM filesystem support"
+	bool "Generic uClinux RAM/ROM filesystem support"
 	depends on MTD_PARTITIONS && MTD_RAM && !MMU
 	help
 	  Map driver to support image based filesystems for uClinux.