random: garbage collect the RANDOM_PURE_OCTEON entropy source

It was used for Octeon MIPS and all producers have been removed
from the source tree.

Reviewed by: emaste
Differential Revision:	https://reviews.freebsd.org/D53146

sys/dev/random/fenestrasX/fx_pool.c

@@ -167,9 +167,6 @@ static const struct fxrng_ent_char {
 	[RANDOM_RANDOMDEV] = {
 		.entc_cls = &fxrng_lo_push,
 	},
-	[RANDOM_PURE_OCTEON] = {
-		.entc_cls = &fxrng_hi_push,	/* Could be made pull. */
-	},
 	[RANDOM_PURE_SAFE] = {
 		.entc_cls = &fxrng_hi_push,
 	},

sys/dev/random/random_harvestq.c

@@ -661,8 +661,7 @@ static const char *random_source_descr[ENTROPYSOURCE] = {
 	[RANDOM_UMA] = "UMA",
 	[RANDOM_CALLOUT] = "CALLOUT",
 	[RANDOM_RANDOMDEV] = "RANDOMDEV", /* ENVIRONMENTAL_END */
-	[RANDOM_PURE_OCTEON] = "PURE_OCTEON", /* PURE_START */
+	[RANDOM_PURE_SAFE] = "PURE_SAFE", /* PURE_START */
-	[RANDOM_PURE_SAFE] = "PURE_SAFE",
 	[RANDOM_PURE_GLXSB] = "PURE_GLXSB",
 	[RANDOM_PURE_HIFN] = "PURE_HIFN",
 	[RANDOM_PURE_RDRAND] = "PURE_RDRAND",

sys/sys/random.h

@@ -89,8 +89,7 @@ enum random_entropy_source {
 	RANDOM_ENVIRONMENTAL_END = RANDOM_RANDOMDEV,
 	/* Fast hardware random-number sources from here on. */
 	RANDOM_PURE_START,
-	RANDOM_PURE_OCTEON = RANDOM_PURE_START,
+	RANDOM_PURE_SAFE = RANDOM_PURE_START,
-	RANDOM_PURE_SAFE,
 	RANDOM_PURE_GLXSB,
 	RANDOM_PURE_HIFN,
 	RANDOM_PURE_RDRAND,