MLK-18675-20 brcmfmac: Support wake on ping packet

MLK-18675-20 brcmfmac: Support wake on ping packet

FMAC driver need to provide a dummy wowlan filter for kernel and
provided the well configured wowlan stack. So the system will
keep driver in connected state in suspend mode and can be wake
up by ping packet.

Enable unicast packet filter before system suspend and
disable it after resume.

Signed-off-by: Lo-Hsiang Lo <double.lo@cypress.com>
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
(Vipul: Fixed merge conflicts)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>