gallium: add type parameter to create_fence_fd

gallium: add type parameter to create_fence_fd

An fd can potentially have different types of objects backing it.
Specifying the type helps us make sure we treat the FD correctly.

This is in preparation to allow importing syncobj fence FDs in addition
to native sync FDs.

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>