rockchip: clk: rk3368: use correct (i.e. 'rk3368_clk_priv') structure for auto-alloc

The clk driver for the RK3368 picked the wrong data structure's size
for its auto-alloc size: the size was calculated on the structure
representing the CRU hardware block instead of the priv structure.
As the CRU's register file is much larger than the driver's priv,
this did not cause any pain (except wasting memory).

Fix this by using the correct data structure's size.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>