wireless: mwifiex: initial commit for Marvell mwifiex driver

This driver adds WiFi support for Marvell 802.11n based chipsets
with SDIO interface. Currently only SD8787 is supported. More
chipsets will be supported later.

drivers/net/wireless/mwifiex/

Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kiran Divekar <dkiran@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: Marc Yang <yangyang@marvell.com>
Signed-off-by: Ramesh Radhakrishnan <rramesh@marvell.com>
Signed-off-by: Frank Huang <frankh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>