dt-bindings: clock: add ID for eMMC for EN7581

Add ID for eMMC for EN7581. This is to control clock selection of eMMC
between 200MHz and 150MHz.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250113231030.6735-4-ansuelsmth@gmail.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>