Revert "regmap: Add bulk read/write callbacks into regmap_config"

This reverts commit f36ef837 which is
commit d77e7456 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I867c560a3d0ee032b02cdc52c47c0722f73479a3
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>