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 969cf8d678720fba24b039bb7005c6639ea4aa58

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 5d23304f54e29c42fd06b076eb61ea2674594576
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>