regulator: mem-acc: Select multiple override ACC configurations

Add logic to choose between multiple ACC override configurations
based on the override fuse. The scheme maps each possible override
fuse value to a override configuration.

Update 8952 ACC DT configuration accordingly.

CRs-Fixed: 896763
Change-Id: Ia5cc395edab3d9fe34c94af5457462a677b59399
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>