dm: core: Update uclass_find_next_free_req_seq() args

At present this is passed a uclass ID and it has to do a lookup. The
callers all have the uclass pointer, except for the I2C uclass where the
code will soon be deleted.

Update the argument to a uclass * instead of an ID since it is more
efficient.

Signed-off-by: Simon Glass <sjg@chromium.org>
4 files changed