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

This reverts commit 31642219 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: I30c32ccdd4216c9f29ca4aa5c432518c203f444f
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>