mwifiex: module parameter for deep sleep configuration

This patch adds module parameter for auto deepsleep configuration.
By default, module_param is 0 and auto deep sleep is enabled.
If mwifiex driver is loaded with disable_auto_ds=1, deep sleep
configuration would not be downloaded to FW and FW would not enter
deepsleep upon initializing.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>