iwlwifi: generic init calibrations framework

This patch allows variable number of init calibrations and allows
addition new HW.

This patch also fixes critical bug. Only last calibration result
was applied. On reception of one calibration result all the calibration
was freed.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>