component: add support for releasing match data

The component helper treats the void match data pointer as an opaque
object which needs no further management.  When device nodes being
passed, this is not true: the caller should pass its refcount to the
component helper, and there should be a way to drop the refcount when
the matching information is destroyed.

This patch provides a per-match release method in addition to the match
method to solve this issue.  Rather than using component_match_add(),
users should use component_match_add_release() which takes an additional
function pointer for releasing this reference.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2 files changed