Kernel: Cleanup entering acpi mode

There is no need to pass the current mode as an argument as ACPI has
access to that info either way.

Only route INTx objects when using ACPI, they won't be used otherwise

kernel/include/kernel/ACPI/ACPI.h

@@ -23,11 +23,7 @@ namespace Kernel::ACPI
 
 		const SDTHeader* get_header(BAN::StringView signature, uint32_t index);
 
-		// mode
-		//   0: PIC
-		//   1: APIC
-		//   2: SAPIC
-		BAN::ErrorOr<void> enter_acpi_mode(uint8_t mode);
+		BAN::ErrorOr<void> enter_acpi_mode();
 
 		BAN::ErrorOr<void> initialize_acpi_devices();