compat: add efi_enabled()

Upstream commit 3e1afb65a6fa6d964c1bbc9b2f4fc89c31d42d1a

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
compat: netdev_set_default_ethtool_ops() is not in kernel 3.7.5

Upstream commit 726d9b2ca3f75cba9f1d03e519c2b2e8bf6523a7

netdev_set_default_ethtool_ops() should be added to compat for every
3.7.X series kernel as it is also not in 3.7.5.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
compat: check if efi_enabled() was already backported

Upstream commit 28c1dde0df2c9e01e8d57a774687734ed21bd208

efi_enabled() gets backported to older kernel versions and if this is
the case compat should not try to do the same.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>