Move the qemu helper to the integration tests

Signed-off-by: Noah Knegt <git@noahknegt.com>

kernel/src/qemu.rs

@@ -1,15 +0,0 @@
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(u32)]
-pub enum QemuExitCode {
-    Success = 0x10,
-    Failed = 0x11,
-}
-
-pub fn exit_qemu(exit_code: QemuExitCode) {
-    use x86_64::instructions::port::Port;
-
-    unsafe {
-        let mut port = Port::new(0xf4);
-        port.write(exit_code as u32);
-    }
-}