qcacld-3.0: Advertise BSS transition enabled in extended capabilities

When BTM config is disabled in the supplicant, the BSS
transition bit (19) of the extended capabilities will be
disabled. If BTM offload is enabled, currently driver still
advertises that the BSS transition bit(19) as disabled. This
results in AP disabling 11v for this STA.

Advertise the BSS transition bit (19) as enabled in the extended
capabilities if btm_offload ini bit 1 is enabled.

Change-Id: I7c1977294a2e166321951ee0ec31f18929c42176
CRs-Fixed: 2455919