bus: ti-sysc: change in a normal driver

The module defines a duplicate uclass driver for UCLASS_SIMPLE_BUS, but
it is not allowed. This breaks of-platdata and makes the result
non-deterministic.

The driver does not need to be an uclass driver, so lets remove it. I
had turned it into an uclass driver because I thought wrongly it had to
call the dm_scan_fdt_dev routine to work properly, but some tests on the
board have shown otherwise.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Simon Glass <sjg@chromium.org>