random(4): Add CCP random source definitions

The implementation will follow (D12723).  For now, get the changes to
commit-protected files out of the way.

Approved by:	secteam (gordon)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D13925

sys/dev/random/random_harvestq.c

@@ -304,6 +304,7 @@ static const char *random_source_descr[ENTROPYSOURCE] = {
 	[RANDOM_PURE_RNDTEST] = "PURE_RNDTEST",
 	[RANDOM_PURE_VIRTIO] = "PURE_VIRTIO",
 	[RANDOM_PURE_BROADCOM] = "PURE_BROADCOM",
+	[RANDOM_PURE_CCP] = "PURE_CCP",
 	/* "ENTROPYSOURCE" */
 };
 

sys/sys/random.h

@@ -94,6 +94,7 @@ enum random_entropy_source {
 	RANDOM_PURE_RNDTEST,
 	RANDOM_PURE_VIRTIO,
 	RANDOM_PURE_BROADCOM,
+	RANDOM_PURE_CCP,
 	ENTROPYSOURCE
 };