mwifiex: add support for SDIO card reset

When command timeout happens due to a bug in firmware/hardware,
the timeout handler just prints some debug information. User is
unable to reload the driver in this case.

Inspired by 9a821f5d "libertas: add sd8686 reset_card support",
this patch adds card reset support for SDIO interface when
command timeout happens. If the SDIO host contoller supports
MMC_POWER_OFF|UP|ON operations, the chip will be reset and the
firmware will be re-downloaded.

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>