clk: at91: sama7g5: switch to parent_hw and parent_data

Switch SAMA7G5 clocks to use parent_hw and parent_data. Having
parent_hw instead of parent names improves to clock registration
speed and re-parenting. Extra time saved on registration is
~250us when running at 800MHz.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20230615093227.576102-11-claudiu.beznea@microchip.com