Add revoke.c to the jbd2 Makefile and update its includes to use the
compatibility layer.
Add stubs for hash_64 and __find_get_block_nonatomic()
Remove JBD2 revoke function stubs that are now provided by revoke.c.
Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>