clk: renesas: rcar-usb2-clock-sel: Fix kernel NULL pointer dereference

The probe was manually passing NULL instead of dev to devm_clk_hw_register.
This caused a Unable to handle kernel NULL pointer dereference error.
Fix this by passing 'dev'.

Signed-off-by: Adam Ford <aford173@gmail.com>
Fixes: a20a40a8

 ("clk: renesas: rcar-usb2-clock-sel: Fix error handling in .probe()")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>