soc: qcom: apr: Add avs/audio tracking functionality

Use PDR helper functions to track the protection domains that the apr
services are dependent upon on SDM845 SoC, specifically the "avs/audio"
service running on ADSP Q6.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200312120842.21991-4-sibis@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

include/linux/soc/qcom/apr.h

@@ -85,6 +85,7 @@ struct apr_device {
 	uint16_t	domain_id;
 	uint32_t	version;
 	char name[APR_NAME_SIZE];
+	const char *service_path;
 	spinlock_t	lock;
 	struct list_head node;
 };