soc: qcom: rpmhpd: Provide some missing struct member descriptions

Fixes the following W=1 kernel build warning(s):

 drivers/soc/qcom/rpmhpd.c:52: warning: Function parameter or member 'parent' not described in 'rpmhpd'
 drivers/soc/qcom/rpmhpd.c:52: warning: Function parameter or member 'corner' not described in 'rpmhpd'
 drivers/soc/qcom/rpmhpd.c:52: warning: Function parameter or member 'active_corner' not described in 'rpmhpd'

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201103152838.1290217-22-lee.jones@linaro.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/soc/qcom/rpmhpd.c

@@ -24,9 +24,12 @@
  * struct rpmhpd - top level RPMh power domain resource data structure
  * @dev:		rpmh power domain controller device
  * @pd:			generic_pm_domain corrresponding to the power domain
+ * @parent:		generic_pm_domain corrresponding to the parent's power domain
  * @peer:		A peer power domain in case Active only Voting is
  *			supported
  * @active_only:	True if it represents an Active only peer
+ * @corner:		current corner
+ * @active_corner:	current active corner
  * @level:		An array of level (vlvl) to corner (hlvl) mappings
  *			derived from cmd-db
  * @level_count:	Number of levels supported by the power domain. max