mfd: devicetree: qcom_rpm: Document IPQ8064 resources

The IPQ8064 SoC has several RPM-controlled resources, an NSS fabrick
clock and four regulator resources.  Provide definitions for them.

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
[sboyd@codeaurora.org: Drop regulator part of binding]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>