Revert "OPP: Introduce dev_pm_opp_get_freq_indexed() API"

This reverts commit 7f73098b which is
commit 5f756d03 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: I2e361b5c7e9306d76e606eaa5eb1fa87af5eed28
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>