Copy the flags set from physmap MemoryType over on scheme mmap

Propagating flags like uncachable or writecombining is necessary both
for correctness and for performance.

src/scheme/memory.rs

@@ -1,6 +1,6 @@
 use core::num::NonZeroUsize;
 
-use alloc::{sync::Arc, vec::Vec};
+use alloc::sync::Arc;
 use rmm::PhysicalAddress;
 
 use crate::{
@@ -153,6 +153,7 @@ impl MemoryScheme {
                         // Default
                         MemoryType::Writeback => (),
 
+                        // When adding a new flag make sure to modify Grant::borrow_fmap to copy the flag over
                         MemoryType::WriteCombining => page_flags = page_flags.write_combining(true),
                         MemoryType::Uncacheable => page_flags = page_flags.uncacheable(true),
                         MemoryType::DeviceMemory => page_flags = page_flags.device_memory(true),