mwifiex: add support for Marvell SD8897 chipset

Some of the key differences between SD8897 and older chipsets
are as follows:

a) sdio mpa_rx and mpa_tx ports have been increased from 16 to 32
b) Same is the case with read/write bitmap that one receives from
   mpa_reg read
c) aggregation packet count doubled from 8 to 16
d) Most of key reg addresses are changed
e) There is a separate command or control port
f) Now command rx/tx_done have new interrupts

1. 'supports_sdio_new_mode' flag is added to handle (a) and (b).
2. (c) and (d) are taken care of by filling chip specific
   information in global structurei (mwifiex_sdio_sd8897).
3. For older chipsets, port 0 was cmd port and port 1->15 were
   data port. Therefore we had CTRL_PORT_MASK to differentiate
   port type. Now these changes are under 'has_control_mask' flag.

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Frank Huang <frankh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>