mtd, ubi, ubifs: update for the sync with linux v3.14

while playing with the new mtd/ubi/ubifs sync, found some
small updates for it:

- add del_mtd_partition() to include/linux/mtd/mtd
- mtd: add a debug_printf
- remove some not used functions

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Tom Rini <trini@ti.com>
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index b7b4757..e6cfd55 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -480,6 +480,7 @@
 #ifdef __UBOOT__
 /* drivers/mtd/mtdcore.h */
 int add_mtd_device(struct mtd_info *mtd);
+int del_mtd_device(struct mtd_info *mtd);
 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);
 int del_mtd_partitions(struct mtd_info *);
 #endif