Revert "OPP: Introduce dev_pm_opp_find_freq_{ceil/floor}_indexed() APIs"

This reverts commit 92fcb466 which is
commit 142e17c1 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: I1af7c9d9e49c81fae8706dc5fcb1f80e5aaac0b0
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>