backports: fix module version

backports: fix module version

Adding multiple MODULE_VERSION statements doesn't work on
kernels before 3.8 (where __UNIQUE_ID was introduced) so
just use a single line:

$ /sbin/modinfo .../net/mac80211/mac80211.ko
filename:       .../net/mac80211/mac80211.ko
license:        GPL
description:    IEEE 802.11 subsystem
version:        backported from Linux (next-20130405-0-g7df052b) using backports 6648f05
srcversion:     CD64527389072C2F603DD61
depends:        cfg80211,compat
vermagic:       3.8.0 SMP mod_unload modversions
parm:           max_nullfunc_tries:Maximum nullfunc tx tries before disconnecting (reason 4). (int)
parm:           max_probe_tries:Maximum probe tries before disconnecting (reason 4). (int)
parm:           probe_wait_ms:Maximum time(ms) to wait for probe response before disconnecting (reason 4). (int)
parm:           ieee80211_default_rc_algo:Default rate control algorithm for mac80211 to use (charp)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>