iwlwifi: mvm: debugfs for phy-integration-ver

commit 33fa519a upstream.

Add debugfs file to print the PHY integration version.
File name is: phy_integration_ver

Signed-off-by: Dror Moshe <drorx.moshe@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210117164916.f5127d919656.Ib714f444390b39cbbf7eb143c5440cc890385981@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>