iwlwifi: mvm: update UAPSD support TLV bits

Change old UAPSD bit to PM_CMD_SUPPORT, and add a new bit to indicate
real UAPSD support.
Don't use UAPSD when the firmware doesn't support it.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>