datapath: remove HAVE_MAC_RAW

datapath: remove HAVE_MAC_RAW

This was causing it to fail against latest RT kernels, with following errors:

	In file included from /home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/compat/include/linux/if_vlan.h:6:0,
	                 from /home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/actions.c:29:
	/home/arm/work/kernel/linaro/lng/lng.git/include/linux/if_vlan.h: In function vlan_insert_tag:
	/home/arm/work/kernel/linaro/lng/lng.git/include/linux/if_vlan.h:197:5: error: struct sk_buff has no member named mac
	In file included from /home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/../flow.h:34:0,
	                 from /home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/../datapath.h:31,
	                 from /home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/actions.c:36:
	/home/arm/work/kernel/linaro/lng/lng.git/include/net/inet_ecn.h: In function INET_ECN_set_ce:
	/home/arm/work/kernel/linaro/lng/lng.git/include/net/inet_ecn.h:137:10: error: struct sk_buff has no member named nh
	/home/arm/work/kernel/linaro/lng/lng.git/include/net/inet_ecn.h:142:10: error: struct sk_buff has no member named nh
	/home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/actions.c: In function __pop_vlan_tci:
	/home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/actions.c:72:5: error: struct sk_buff has no member named mac
	make[7]: *** [/home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux/actions.o] Error 1
	make[6]: *** [_module_/home/arm/work/kernel/linaro/lng/openvswitch/datapath/linux] Error 2

Not sure why it was added earlier but my guess is, for earlier RT kernels struct
sk_buff had following variables mac.raw, nh.raw, h.raw instead of mac_header,
network_header, transport_header. And so the hack to rename them in OVS code.
But that's not the case now. RT kernel have mac_header, network_header and
transport_header as parameter and so we don't need this macro at all.

Lets get rid of it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jesse Gross <jesse@nicira.com>