Revert "mwifiex: retrieve correct max_power information in reg_notifier handler"

Revert "mwifiex: retrieve correct max_power information in reg_notifier handler"

This reverts commit 2cb9e8326511fa7a03def6883c6729c3afc8a4a3

We made "34202ee.." because we didn't support custom regulatory rules
at that time. But now we use our own custom regulatory rules, so it
needs to be changed back.

Also, chan->max_power calculations in cfg80211 were broken. Hence we
started using chan->max_reg_power. Now it has got fixed in
following commit.

commit c4797683caf6879248dc8a420dbf10bb57be8751
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date:   Tue Jul 24 08:35:39 2012 +0200

    wireless: reg: restore previous behaviour of chan->max_power calculations

Hence we will use chan->max_power instead of chan->max_reg_power.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>