iwlwifi: fix "MAC in deep sleep" error

This patch fixes the misue of CSR_GP_CNTRL with CSR_RESET address
in polling the CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY bit in
iwl4965_apm_reset(). This causes "MAC in deep sleep" error sometimes.
The patch also fixes the timeout value and the iwl_poll_bit() return
value check.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>