qemu.inc: Add rng-tools to qemu images

This patch adds rng-tools to MACHINE_EXTRA_RRECOMMENDS so that can be
used to provide the additional entropy to prevent hangs in getrandom()
for qemu images

[YOCTO #8681]
[YOCTO #8816]

(From OE-Core rev: cb512c0c189f5a1196da233042113a708243daa0)

Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/conf/machine/include/qemu.inc

@@ -27,3 +27,5 @@ EXTRA_IMAGEDEPENDS += "qemu-native qemu-helper-native"
 
 # Provide the nfs server kernel module for all qemu images
 KERNEL_FEATURES_append_pn-linux-yocto = " features/nfsd/nfsd-enable.scc"
+
+MACHINE_EXTRA_RRECOMMENDS += "rng-tools"