v4: Fixed error handling in __genpd_dev_pm_attach()

This is a re-spin of the series [1] which was adding support for a new
DT binding (assigned-performance-state) and based on the discussions on
that thread [2] it was concluded that we could achieve the same with the
existing 'required-opps' binding instead.

So this series, just drops the new binding and uses required-opps to achieve
the default perf state setting thats needed by some devices.

---
Some devics within power-domains with performance states do not
support DVFS, but still need to vote on a default/static state
while they are active. Add support for this using the 'required-opps'
property in device tree.

[1] https://lore.kernel.org/patchwork/project/lkml/list/?series=501336&state=%2A&archive=both
[2] https://lore.kernel.org/patchwork/patch/1436886/

Rajendra Nayak (2):
  PM / Domains: Add support for 'required-opps' to set default perf
    state
  arm64: dts: sc7180: Add required-opps for i2c

 arch/arm64/boot/dts/qcom/sc7180.dtsi | 24 +++++++++++++++++++++++
 drivers/base/power/domain.c          | 37 +++++++++++++++++++++++++++++++++---
 include/linux/pm_domain.h            |  1 +
 3 files changed, 59 insertions(+), 3 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation