mwifiex: store SDIO chip specific information in separate structure

Register addresses, firmware name and some macros are specific to
a chip. They are stored in a new structure.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>