mtd: make MTD_CONCAT support mandatory

Move mtdconcat to be an integral part of the mtd core. It's a tiny bit
of code, which bears 'say Y if you don't know what to do' note in the
Kconfig. OTOH there are several ugly ifdefs depending on the MTD_CONCAT.
So, making MTD_CONCAT support mandatory will allow us to clean up code a
lot.

Kconfig entry is changed to be a bool defaulting to Y, so all code
pieces depending on it, will have MTD_CONCAT Kconfig symbol and
CONFIG_MTD_CONCAT define. This will be removed in one of next patches.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Stefan Roese <sr@denx.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/Kconfig

@@ -34,7 +34,8 @@ config MTD_TESTS
 	  various checks and verifications when loaded.
 
 config MTD_CONCAT
-	tristate "MTD concatenating support"
+	bool
+	default y
 	help
 	  Support for concatenating several MTD devices into a single
 	  (virtual) one. This allows you to have -for example- a JFFS(2)

drivers/mtd/Makefile

@@ -4,11 +4,10 @@
 
 # Core functionality.
 obj-$(CONFIG_MTD)		+= mtd.o
-mtd-y				:= mtdcore.o mtdsuper.o
+mtd-y				:= mtdcore.o mtdsuper.o mtdconcat.o
 mtd-$(CONFIG_MTD_PARTITIONS)	+= mtdpart.o
 mtd-$(CONFIG_MTD_OF_PARTS)	+= ofpart.o
 
-obj-$(CONFIG_MTD_CONCAT)	+= mtdconcat.o
 obj-$(CONFIG_MTD_REDBOOT_PARTS) += redboot.o
 obj-$(CONFIG_MTD_CMDLINE_PARTS) += cmdlinepart.o
 obj-$(CONFIG_MTD_AFS_PARTS)	+= afs.o