iwlwifi: add disable rf calibration support for 6000g2a and 6000g2b

Radio calibration (chain noise and sensitivity) should be allowed to
be disabled from debugfs if compiled with CONFIG_IWLWIFI_DEBUGFS. For both
6000g2a and 6000g2b, the parameters are missing in "cfg", which cause
user can not disable the radio calibration manually; add the support to
allow the operation.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>