clk: en7523: move clock_register in hw_init callback

clk: en7523: move clock_register in hw_init callback

Move en7523_register_clocks routine in hw_init callback.
Introduce en7523_clk_hw_init callback for EN7523 SoC.
This is a preliminary patch to differentiate IO mapped region between
EN7523 and EN7581 SoCs in order to access chip-scu IO region
<0x1fa20000 0x384> on EN7581 SoC as syscon device since it contains
miscellaneous registers needed by multiple devices (clock, pinctrl ..).

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/20241112-clk-en7581-syscon-v2-3-8ada5e394ae4@kernel.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>