Reuse the descriptor parsing functionality to keep the same output format
as the original ptdump code. In order for this to happen, move the state
tracking objects into a common header.

[maz: Fixed note_page() stub as suggested by Will]
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240909124721.1672199-3-sebastianene@google.comSigned-off-by: Marc Zyngier <maz@kernel.org>