ARM: dts: msm: use active-only VDD_MX regulator for APC0/1 on msm8994

Update the APC0 and APC1 cpr-regulator devices to use the
active-only VDD_MX regulator pm8994_s2_corner_ao instead of the
active + sleep VDD_MX regulator pm8994_s2_corner.  This ensures
that the RPM can lower VDD_MX to its retention voltage during RPM
assisted power collapse.

Change-Id: I75143254dc9f0c37edacd2c68817e3c96d5715d0
Signed-off-by: David Collins <collinsd@codeaurora.org>