Fix vuart symlink udev rule

The rule was not creating the /dev/ttyVUART0 rule.

```
root@palmetto:~# udevadm info -q all /dev/ttyS0
P: /devices/platform/ahb/ahb:apb/1e787000.vuart/tty/ttyS0
N: ttyS0
E: DEVNAME=/dev/ttyS0
E: DEVPATH=/devices/platform/ahb/ahb:apb/1e787000.vuart/tty/ttyS0
E: MAJOR=4
E: MINOR=64
E: SUBSYSTEM=tty
E: TAGS=:systemd:
E: USEC_INITIALIZED=22674274
```

```
root@palmetto:~# systemctl status dev-ttyVUART0.device --no-pager
● dev-ttyVUART0.device
   Loaded: loaded
   Active: inactive (dead)

Nov 07 05:43:37 palmetto systemd[1]: dev-ttyVUART0.device: Job dev-ttyVUART0.device/start timed out.
Nov 07 05:43:37 palmetto systemd[1]: Timed out waiting for device dev-ttyVUART0.device.
Nov 07 05:43:37 palmetto systemd[1]: dev-ttyVUART0.device: Job dev-ttyVUART0.device/start failed with result 'timeout'.
```

This just sits there without returning:

```
root@palmetto:~# systemctl start dev-ttyVUART0.device
```

This is the reason udev does not trigger due to the lpc address on this system
being set to 0x417 when the rule expects 0x3f8:

```
root@palmetto:~# cat /sys/devices/platform/ahb/ahb\:apb/1e787000.vuart/lpc_address
0x417
```

- `obmc-console-server` is launched when `/dev/ttyVUART0` is created.
- `/dev/ttyVUART0` is created when a device with `lpc_address` of `0x3f8` is created
- `lpc_address` is configured by obmc-console-server.
- GOTO 10;

A fix would be to match the udev rule on the address of the peripheral. This is
what Cedric's original patch did:

```
SUBSYSTEM=="tty", ATTR{iomem_base}=="0x1E787000", SYMLINK+="tty-host"
```

Use the iomem_base in place of the lpc_address condition. The rule was
not matching with the driver==aspeed_vuart condition, so that was removed
as well.

Fixes: openbmc/openbmc#749
Fixes: openbmc/openbmc#718
Fixes: openbmc/openbmc#706

Change-Id: Ia55f47a84d657ab9572a8b0495420b1f56e16c02
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/meta-openbmc-bsp/meta-aspeed/common/recipes-core/udev-aspeed-vuart/udev-aspeed-vuart/61-aspeed-vuart.rules b/meta-openbmc-bsp/meta-aspeed/common/recipes-core/udev-aspeed-vuart/udev-aspeed-vuart/61-aspeed-vuart.rules
index 98ac36d..f9b93c9 100644
--- a/meta-openbmc-bsp/meta-aspeed/common/recipes-core/udev-aspeed-vuart/udev-aspeed-vuart/61-aspeed-vuart.rules
+++ b/meta-openbmc-bsp/meta-aspeed/common/recipes-core/udev-aspeed-vuart/udev-aspeed-vuart/61-aspeed-vuart.rules
@@ -1 +1 @@
-SUBSYSTEM=="tty", DRIVERS=="aspeed-vuart",ATTRS{lpc_address}=="0x3f8", SYMLINK+="ttyVUART0", TAG+="systemd"
+SUBSYSTEM=="tty", ATTRS{iomem_base}=="0x1E787000", SYMLINK+="ttyVUART0", TAG+="systemd"