mwifiex: add power save parameters in hs_cfg cmd

This patch adds power save parameters(hs_wake_interval and
hs_inactivity_timeout) in host sleep cfg cmd.

Signed-off-by: Shengzhen Li <szli@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>