firmware: arm_scmi: Add SCMI v3.0 sensors descriptors extensions

Add support for new SCMI v3.0 Sensors extensions related to new sensors'
features, like multiple axis and update intervals, while keeping
compatibility with SCMI v2.0 features.

While at that, refactor and simplify all the internal helpers macros and
move struct scmi_sensor_info to use only non-fixed-size typing.

Link: https://lore.kernel.org/r/20201119174906.43862-3-cristian.marussi@arm.com


Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>