drm/asahi: Map all reserved-regions as cached

There seems to be no reason to map any of this uncached, and this makes
it possible to remove `no-map` from the device tree entries without
breaking under u-boot/EFI.

Signed-off-by: Asahi Lina <lina@asahilina.net>

Author: hoshinolina

drivers/gpu/drm/asahi/mmu.rs

@@ -1540,8 +1540,8 @@ impl Uat {
     /// Creates the reference-counted inner data for a new `Uat` instance.
     #[inline(never)]
     fn make_inner(dev: &driver::AsahiDevice) -> Result<Arc<UatInner>> {
-        let handoff_rgn = Self::map_region(dev.as_ref(), c_str!("handoff"), HANDOFF_SIZE, false)?;
-        let ttbs_rgn = Self::map_region(dev.as_ref(), c_str!("ttbs"), SLOTS_SIZE, false)?;
+        let handoff_rgn = Self::map_region(dev.as_ref(), c_str!("handoff"), HANDOFF_SIZE, true)?;
+        let ttbs_rgn = Self::map_region(dev.as_ref(), c_str!("ttbs"), SLOTS_SIZE, true)?;
 
         let handoff = unsafe { &(handoff_rgn.map.as_ptr() as *mut Handoff).as_ref().unwrap() };