Documentation: nova: Update the todo list

This small patch updates the nova todo list to
remove some tasks that have been solved lately:
* COHA is solved in this patch series
* TRSM was solved recently [1]

[1] https://lore.kernel.org/rust-for-linux/[e-mail]/

Signed-off-by: Daniel del Castillo <[e-mail]>
[[e-mail]: set prefix to "Documentation: nova:".]
Signed-off-by: Alexandre Courbot <[e-mail]>
Message-ID: <[e-mail]>

Documentation/gpu/nova/core/todo.rst

···
 | Complexity: Beginner
 | Link: https://docs.rs/num/latest/num/trait.FromPrimitive.html
 
-Conversion from byte slices for types implementing FromBytes [TRSM]
--------------------------------------------------------------------
-
-We retrieve several structures from byte streams coming from the BIOS or loaded
-firmware. At the moment converting the bytes slice into the proper type require
-an inelegant `unsafe` operation; this will go away once `FromBytes` implements
-a proper `from_bytes` method.
-
-| Complexity: Beginner
-
-CoherentAllocation improvements [COHA]
---------------------------------------
-
-`CoherentAllocation` needs a safe way to write into the allocation, and to
-obtain slices within the allocation.
-
-| Complexity: Beginner
-| Contact: Abdiel Janulgue
-
 Generic register abstraction [REGA]
 -----------------------------------