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 34202e28fe7fc8551313f9a035a8857db83de757

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 5e31fc0815a4e2c72b1b495fe7a0d8f9bfb9e4b4
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>