Add configuration for gpio pin used to send strobe to wlan hw.
The host driver will latch the current time and toggle the gpio
to generate a strobe to wlan hw.
The tsf will be latched on detecting the strobe and it will be
made available in a register for sw access.
The wlan fw will read this tsf and report it to driver using tsf event.
Change-Id: I4365d97d22836ddbbd2bf9913d4f723e5a870369
CRs-Fixed: 2495152