habanalabs: fix mmu node address resolution in debugfs

The address resolution via debugfs was not taking into consideration the
page offset, resulting in a wrong address.

Signed-off-by: Yuri Nudelman <ynudelman@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>