[MTD] [NAND] rename at91_nand -> atmel_nand: file names and Kconfig

The AT91 NAND driver needs just a few tiny modifications to work on
AVR32 as well. Rename it atmel_nand to reflect this.

Also move the ECC register definitions into drivers/mtd/nand since they
are only useful to the atmel_nand driver, and get rid of the useless
filename at the top of each file.

Signed-off-by: Håvard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index d95a10c..d772581 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -23,7 +23,7 @@
 obj-$(CONFIG_MTD_NAND_NANDSIM)		+= nandsim.o
 obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x_nand.o
 obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
-obj-$(CONFIG_MTD_NAND_AT91)		+= at91_nand.o
+obj-$(CONFIG_MTD_NAND_ATMEL)		+= atmel_nand.o
 obj-$(CONFIG_MTD_NAND_CM_X270)		+= cmx270_nand.o
 obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
 obj-$(CONFIG_MTD_NAND_PXA3xx)		+= pxa3xx_nand.o