wl12xx: add support for HW dynamic PS

wl12xx: add support for HW dynamic PS

FW now supports dynamic PS so we don't need to use mac80211 support.
FW will go to PSM after a specified timeout with no Rx/Tx traffic.
- Changed FW API to include new PS mode (AUTO_MODE) and including timeout parameter
- The default PS mode would be dynamic PS
- Default timeout is 100ms (same as it used to be in mac80211)
- Avoid using mac80211 APIs to disable/enable dynamic PS as we're not
using mac80211 PS control anymore.
- COEX is handled by the FW while in dynamic PS so removed
handling of SOFT_GEMINI

Signed-off-by: Eyal Shapira <eyal@wizery.com>
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>