qcacld-3.0: Remove #ifdef FEATURE_WLAN_LFR from HDD

The condition #ifdef WLAN_FEATURE_LFR is used to include some of
the roaming code. It has been defined for all the recent driver
builds. Roaming code underneath is permanent part of the driver.

Remove #ifdef FEATURE_WLAN_LFR compiler flag from HDD so that the code
will always be compiled in.

CRs-Fixed: 936683
Change-Id: If5010bc1470a35b2f1516a5c5d10461352fd87fc