MAINTAINERS: Add missing T: entry for FIRMWARE LOADER
The firmware loader is maintained through the driver-core tree, hence
add a corresponding T: entry.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260120123925.28267-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>