package/rng-tools: powerpc64le requires libgcrypt

This patch adds the libgcrypt dependency for rngd_darn support
when building for the specific BR2_powerpc64le archtecture.
This entropy source is only enabled when powerpc64le is selected.

Fixes:
http://autobuild.buildroot.net/results/a41/a412ccef864e8279dcc917e106b5f7b515ed95da/

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/rng-tools/Config.in

@@ -1,11 +1,11 @@
 config BR2_PACKAGE_RNG_TOOLS
 	bool "rng-tools"
-	depends on BR2_PACKAGE_LIBGPG_ERROR_ARCH_SUPPORTS || !(BR2_i386 || BR2_x86_64) # libgcrypt
+	depends on BR2_PACKAGE_LIBGPG_ERROR_ARCH_SUPPORTS || !(BR2_i386 || BR2_x86_64 || BR2_powerpc64le) # libgcrypt
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_PACKAGE_ARGP_STANDALONE if BR2_TOOLCHAIN_USES_UCLIBC || BR2_TOOLCHAIN_USES_MUSL
 	select BR2_PACKAGE_JITTERENTROPY_LIBRARY
-	# For rdrand ligcrypt is required and it's not obvious to users
-	select BR2_PACKAGE_LIBGCRYPT if BR2_i386 || BR2_x86_64
+	# For rdrand & darn ligcrypt is required and it's not obvious to users
+	select BR2_PACKAGE_LIBGCRYPT if BR2_i386 || BR2_x86_64 || BR2_powerpc64le
 	select BR2_PACKAGE_LIBSYSFS
 	help
 	  Daemon to use hardware random number generators.