staging: brcm80211: remove tsf retrieval from wlc_bmac.c

Upon receiving a packet the lowest 32 bits of tsf are filled in
by wlc_bmac in wlc_bmac_recv, but this is not useful as wlc_main
needs to reconstruct 64 bit tsf which is retrieves to recover the
actual tsf value at which packet is received. Therefore tsf
retrieval is removed from wlc_bmac.c.

Cc: devel@linuxdriverproject.org
Cc: linux-wireless@vger.kernel.org
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Henry Ptasinski <henryp@broadcom.com>
Cc: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>