Kernel: Restore setting i8042 scan code set to scan code set 2 sequence

This seems to work perfectly OK on my ICH7 test machine and also it
works on QEMU, so it is probably OK to restore this.
This will ensure we always get scan code set 1 input, because we enable
scan code set 2 and PS/2 translation on the first (keyboard) port.

Kernel/Arch/x86_64/ISABus/I8042Controller.cpp

@@ -176,6 +176,11 @@ UNMAP_AFTER_INIT ErrorOr<void> I8042Controller::detect_devices()
             configuration |= I8042ConfigurationFlag::FirstPS2PortClock;
             m_keyboard_device = nullptr;
             SpinlockLocker lock(m_lock);
+            // NOTE: Before setting the actual scan code set, stop packet streaming entirely.
+            TRY(send_command(HIDDevice::Type::Keyboard, I8042Command::DisablePacketStreaming));
+            TRY(do_wait_then_write(I8042Port::Buffer, I8042Command::SetScanCodeSet));
+            TRY(do_wait_then_write(I8042Port::Buffer, 0x2));
+
             TRY(do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration));
             TRY(do_wait_then_write(I8042Port::Buffer, configuration));
         } else {

Kernel/Arch/x86_64/ISABus/I8042Controller.h

@@ -34,6 +34,7 @@ enum I8042Command : u8 {
     GetDeviceID = 0xF2,
     SetSampleRate = 0xF3,
     EnablePacketStreaming = 0xF4,
+    DisablePacketStreaming = 0xF5,
     SetDefaults = 0xF6,
     Reset = 0xFF,
 };