clk: meson: eeclk: add init regs

Like the PLL and MPLL, the controller may require some magic setting to
be applied on startup.

This is needed when the initial setting is not applied by the boot ROM.
The controller need to do it when the setting applies to several clock,
like all the MPLLs in the case of g12a.

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