soc/tegra: pmc: Document core domain fields

These fields are used to track the state of the core domain. Add basic
descriptions so that kerneldoc can be properly generated for them.

Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/soc/tegra/pmc.c

@@ -394,6 +394,8 @@ struct tegra_pmc_soc {
  * @domain: IRQ domain provided by the PMC
  * @irq: chip implementation for the IRQ domain
  * @clk_nb: pclk clock changes handler
+ * @core_domain_state_synced: flag marking the core domain's state as synced
+ * @core_domain_registered: flag marking the core domain as registered
  */
 struct tegra_pmc {
 	struct device *dev;