aspeed: conf: machine: move vuart udev rule

Instead of setting MACHINE_EXTRA_RDEPENDS in each SOC specific include
file, just set it once in aspeed.inc.

Use MACHINE_EXTRA_RRECOMMENDS as the udev rule is definitely not
required and should be removable via BAD_RECOMMENDATIONS.

Change-Id: I78a803a424bd29f7b375b88169c1819387885ca6
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/conf/machine/include/aspeed.inc b/conf/machine/include/aspeed.inc
index 8b3b4f9..a8d2a3b 100644
--- a/conf/machine/include/aspeed.inc
+++ b/conf/machine/include/aspeed.inc
@@ -14,6 +14,8 @@
 INITRAMFS_IMAGE ?= "aspeed-image-initramfs"
 INITRAMFS_FSTYPES ?= "cpio.xz"
 
+MACHINE_EXTRA_RRECOMMENDS += "udev-aspeed-vuart"
+
 MACHINEOVERRIDES =. "aspeed:"
 
 SERIAL_CONSOLES ?= "115200;ttyS4"