cmd: Correct dependency for CMD_LINK_LOCAL

Given how LIB_RAND is handled now, we should be depending on one of the
implementations and not selecting one of them.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index cd391d4..aaebdfd 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -2062,7 +2062,7 @@
 
 config CMD_LINK_LOCAL
 	bool "linklocal"
-	select LIB_RAND
+	depends on (LIB_RAND || LIB_HW_RAND)
 	help
 	  Acquire a network IP address using the link-local protocol