UPSTREAM: binder: relocate binder_alloc_clear_buf()

Move this function up along with binder_alloc_get_page() so that their
prototypes aren't necessary.

No functional change in this patch.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20231201172212.1813387-16-cmllamas@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 254650075
(cherry picked from commit cbc174a6)
Change-Id: I0d3c69c9a26c7415308202c4b7868a36b83d089c
Signed-off-by: Carlos Llamas <cmllamas@google.com>