clk: meson: remove ee input bypass clocks

During probe, bypass clocks (i.e. ee-in-xtal) are made from device-tree
inputs to provide input clocks which can be access through global name.
The cons of this method are the duplicated clocks, means more string
comparison.

Specify parent directly with device-tree clock name.

Remove the bypass clock registration from the ee probe function.

Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>