firmware: arm_scpi: Revert updates made during v4.15 merge window

firmware: arm_scpi: Revert updates made during v4.15 merge window

Revert "Merge tag 'scpi-updates-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into next/drivers"

Paraphrased from email from Kevin Hilman:

Revert ARM SCPI changes since v4.14.

Untested changes caused regressions in SCPI and CPUfreq/DVFS failures
on most Amlogic SoCs.  Changes reverted for v4.15 so they can be better
reviewed and tested.

These ARM SCPI changes caused SCPI regressions resulting in CPUfreq
failures on most Amlogic SoCs (found by kernelci.org.)

Unfortunately, this was not caught in linux-next due to other bugs/panics
on these platforms masking this problem so we've only found it since
we've fixed the other issues.

Since we're already in the -rc cycle, I'd prefer to revert to a known
working state (that of v4.14) rather than finding/reverting a subset,
which would just lead to another untested state.

These changes can then have some time to be better reviewed and tested
and resubmitted for v4.16.

Kevin Hilman has tested this revert on the affected Amlogic SoCs and
verified that we're back to the previous (working) condition.

This reverts commit 1d8afa6d7d53ff8aa88c0d26b373e78ee7bafc60, reversing
changes made to c3c34de014ce3f2e01184f6aa0d04b26661f5ff2.

Reported-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Olof Johansson <olof@lixom.net>