timealarm: EC_TAS_GET_GCP

Return capabilities based on ACPI specification

[9. ACPI-Defined Devices and Device-Specific Objects — ACPI Specification 6.5 documentation](https://uefi.org/specs/ACPI/6.5/09_ACPI_Defined_Devices_and_Device_Specific_Objects.html#gcp-get-capability)