wifi: iwlwifi: prepare for reading WPFC from UEFI

IWL_BIOS_TABLE_LOADER generates the code that determines from what source
to read a BIOS table (ACPI or UEFI).
As we want to read WPFC from UEFI to, iwl_acpi_get_phy_filters needs to
have the prototype that is required by this macro:
receive fwrt and return a int on success/failure.
Do that.

This allowes us to make to version of iwl_acpi_get_phy_filters for non
ACPI builds back to an iniline function.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Pagadala Yesu Anjaneyulu <pagadala.yesu.anjaneyulu@intel.com>
Link: https://patch.msgid.link/20250430151952.8046a2db775b.Ifbcf4168183d3cd635e3e800ec7ecd903e57d361@changeid