net: wireless: bcmdhd: Change DTIM skip policy in suspend

	issue : WiFi continuously disconnects
	Root cause :
	Sometimes we got link down event due to beacon
	lost when device goes to suspend.
	This problem sometimes happens in case that DTIM is 3 and beacon
	100ms because we wake up on 900ms (100ms * 3 * 3) during
	suspend.
	This value(900ms) is too big to STA for sync up with AP time.
	This causes STA out of sync for time with the AP.
	Eventually STA got lost of beacon during long time (4secs).

	Solution :
	If the total dtim skip interval (beacon_interval *
	DTIM * 3) is greater than 300ms, we will not extend DTIM to DTIM
	* 3.
	Instead of that, we will use original value (DTIM) for wake up
	in suspend.
	Bug : 1343127 WiFi continuously disconnects

Signed-off-by: Ecco Park <eccopark@broadcom.com>

Change-Id: I6d89bd1c56127befe4d9606869396ee25b7911ef

Conflicts:
	drivers/net/wireless/bcmdhd/dhd.h
	drivers/net/wireless/bcmdhd/dhd_common.c
net: wireless: bcmdhd: Set MAX_DTIM_ALLOWED_INTERVAL to 600

Change-Id: Ie4d9cac1e0828651a142d64762b251537431ea99
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>