iwlwifi: acpi: evaluate dsm to disable 5.8GHz channels

Evaluate the appropriate DSM from ACPI to set ETSI SRD 5.8GHz
channels to passive or disabled, default behaviour is enabled.
Add enums and refactor evaluation of DSM functions for better
readablity and more informative debug prints.

Signed-off-by: Gil Adam <gil.adam@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200911204056.816130ee75e0.I727a217be7c967a97960b197a816fc053d10c48a@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>