Add a 'gHwFilterMode' ini item to control the DTIM mode hardware
filter. This ini item supersedes 'g_enable_non_arp_bc_hw_filter.'
# disable feature (default)
gHwFilterMode=0
# drop all broadcast frames, except ARP
gHwFilterMode=1
# drop all multicast frames, except ICMPv6
gHwFilterMode=2
# drop all broadcast and multicast frames, except ARP and ICMPv6
gHwFilterMode=3
Change-Id: I6bc8ac7585ffd0a62ab1c57558a798df9b63f2ce
CRs-Fixed: 2040420