airoha: Introduce support for Airoha AN7583 SoC

airoha: Introduce support for Airoha AN7583 SoC

Introduce initial support for Airoha AN7583 SoC and add all the required
patch for basic functionality of the SoC.

Airoha AN7583 is based on Airoha EN7581 SoC with some major changes on
the PHY handling and Serdes. It can be see as a lower spec of EN7581
with modern and simplified implementations.

All the patch are sent upstream and are pending revision. Support for
PCIe and USB will come later as soon as DT structure is accepted
upstream.

Signed-off-by: Christian Marangi <[email protected]>