mtd: m25p80: use the SPI nor framework

Use the new SPI nor framework, and rewrite the m25p80:
 (0) remove all the NOR comands.
 (1) change the m25p->command to an array.
 (2) implement the necessary hooks, such as m25p80_read/m25p80_write.

Tested with the m25p32.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
[Brian: rebased]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/devices/Kconfig

@@ -80,7 +80,7 @@ config MTD_DATAFLASH_OTP
 
 config MTD_M25P80
 	tristate "Support most SPI Flash chips (AT26DF, M25P, W25X, ...)"
-	depends on SPI_MASTER
+	depends on SPI_MASTER && MTD_SPI_NOR_BASE
 	help
 	  This enables access to most modern SPI flash chips, used for
 	  program and data storage.   Series supported include Atmel AT26DF,