region: Add writeat and eraseat support

Implement writeat and eraseat support into the region_device_ops struct.

Change-Id: Iac2cf32e523d2f19ee9e5feefe1fba8c68982f3d
Signed-off-by: Antonello Dettori <dev@dettori.io>
Reviewed-on: https://review.coreboot.org/15318
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
11 files changed