Revert "OPP: Reuse dev_pm_opp_get_freq_indexed()"

This reverts commit e20fd4d3 which is
commit 746de825 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: I13648075fb2871b25977bc22ce6d11bd9e795506
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>