clk: tests: Make clk_register_clk_parent_data_device_driver() common

Rename clk_register_clk_parent_data_device_driver() to
kunit_of_platform_driver_dev() and have it return a struct device
pointer while accepting a match table. This will be useful to
find the device associated with an OF node for more tests than
only the clk_parent_data tests.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
[sboyd@kernel.org: Split out from next patch, carry SoB and
authorship, rename API, return device pointer]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>