UBUNTU: SAUCE: Redpine: enable power save by default for coex mode

BugLink: https://bugs.launchpad.net/bugs/1706991

When Coex mode is enabled, enabling power save will improve
radio sharing. Hence PS on by default flag is set.
Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

ubuntu/rsi/rsi_91x_mac80211.c

@@ -2835,6 +2835,9 @@ int rsi_mac80211_attach(struct rsi_common *common)
 //			    NL80211_FEATURE_P2P_GO_OPPPS);
 #endif
 
+	if (common->coex_mode > 1)
+		wiphy->flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
+
 	status = ieee80211_register_hw(hw);
 	if (status) {
 		ven_rsi_dbg(ERR_ZONE, "Failed to register to mac80211\n");