staging: wilc1000: rename pstrPowerMgmtParam in wilc_set_power_mgmt

This patch renames pstrPowerMgmtParam to pwr_mgmt_info to avoid
camelcase.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>