target/generic: add /dev/ttyAM* device nodes

Add ttyAM support for the ARM AMBA serial ports on the Cirrus EP93xx.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

target/generic/device_table.txt

@@ -72,6 +72,7 @@
 #/dev/ttySA	c	666	0	0	204	5	0	1	3
 /dev/psaux	c	666	0	0	10	1	0	0	-
 #/dev/ppp	c	666	0	0	108	0	-	-	-
+/dev/ttyAM	c	666	0	0	204	16	0	1	3
 /dev/ttyCPM	c	666	0	0	204	46	0	1	4
 /dev/ttyAMA	c	666	0	0	204	64	0	1	4
 /dev/ttySAC	c	666	0	0	204	64	0	1	4