flash/nor: add mrvlqspi flash controller driver

flash/nor: add mrvlqspi flash controller driver

This patch adds support for QSPI flash controller driver for
Marvell's Wireless Microcontroller platform.
For more information please refer,
https://origin-www.marvell.com/microcontrollers/wi-fi-microcontroller-platform/

Following things have been tested on 88MC200 (Winbond W25Q80BV flash chip):
1. Flash sector level erase
2. Flash chip erase
3. Flash write in normal SPI mode
4. Flash fill (write and verify) in normal SPI mode

Change-Id: If4414ae3f77ff170b84e426a35b66c44590c5e06
Signed-off-by: Mahavir Jain <mjain@marvell.com>
Reviewed-on: http://openocd.zylin.com/2280
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>