Backport pm-qos for kernels <= 2.6.24

Backport pm-qos for kernels <= 2.6.24

pm-qos is used by mac80211 and ipw2100. mac80211 uses it for
the dynamic power save to see if to enable it or not upon
recalculation for dynamic ps. It takes the latency registered
to the kernel into account.

Since older kernels do not have pm-qos we simply initialize
pm-qos stuff durng the compat module probe treating pm-qos as if
it were a feature of the compat module. We carry the header file
include/linux/pm_qos_params.h as part of this package, external
kernel drivers just need to ensure they also make use of the
NOSTDINC_FLAGS flag as we do on the top level Makefile to be
able to benefit from a direct port and let external drivers
also inlcude include/linux/pm_qos_params.h as it if it were
in their older kernels.

Cc: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>