refactor: delete some unused code

There are a few unused functions on `BusDevice`. Delete them.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

src/vmm/src/devices/bus.rs

@@ -102,25 +102,6 @@ impl ConstantDevice {
 }
 
 impl BusDevice {
-    pub fn i8042_device_ref(&self) -> Option<&I8042Device> {
-        match self {
-            Self::I8042Device(x) => Some(x),
-            _ => None,
-        }
-    }
-    #[cfg(target_arch = "aarch64")]
-    pub fn rtc_device_ref(&self) -> Option<&RTCDevice> {
-        match self {
-            Self::RTCDevice(x) => Some(x),
-            _ => None,
-        }
-    }
-    pub fn boot_timer_ref(&self) -> Option<&BootTimer> {
-        match self {
-            Self::BootTimer(x) => Some(x),
-            _ => None,
-        }
-    }
     pub fn mmio_transport_ref(&self) -> Option<&MmioTransport> {
         match self {
             Self::MmioTransport(x) => Some(x),
@@ -140,25 +121,6 @@ impl BusDevice {
             _ => None,
         }
     }
-    #[cfg(target_arch = "aarch64")]
-    pub fn rtc_device_mut(&mut self) -> Option<&mut RTCDevice> {
-        match self {
-            Self::RTCDevice(x) => Some(x),
-            _ => None,
-        }
-    }
-    pub fn boot_timer_mut(&mut self) -> Option<&mut BootTimer> {
-        match self {
-            Self::BootTimer(x) => Some(x),
-            _ => None,
-        }
-    }
-    pub fn mmio_transport_mut(&mut self) -> Option<&mut MmioTransport> {
-        match self {
-            Self::MmioTransport(x) => Some(x),
-            _ => None,
-        }
-    }
     pub fn serial_mut(&mut self) -> Option<&mut SerialDevice<std::io::Stdin>> {
         match self {
             Self::Serial(x) => Some(x),