dt-bindings: cache: ax45mp: add 2048 as a supported cache-sets value

The QiLai implementation of this cache controller uses a cache-sets of
2048, and mandates it in an if/else block - but the definition of the
property only permits 1024. Add 2048 as an option, and deny its use
outside of the QiLai.

Fixes: 51b081cd ("dt-bindings: cache: add QiLai compatible to ax45mp")
Reviewed-by: Ben Zong-You Xie <ben717@andestech.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>