Add Xilinx UARTLITE and MPC5200 PSC device files (serial ports)

From: Grant Likely <grant.likely@secretlab.ca>

The Xilinx UART Lite and MPC5200 Programmable Serial Controller (PSC)
devices have dedicated major/minor numbers.  Add them to the device
table data file so they get are present in the root filesystem

target/generic/device_table.txt

@@ -72,6 +72,8 @@
 #/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/ttyPSC	c	666	0	0	204	148	0	1	4
+/dev/ttyUL	c	666	0	0	204	187	0	1	4
 
 # Input stuff
 /dev/input		d	755	0	0	-	-	-	-	-

target/generic/target_skeleton/etc/securetty

@@ -14,3 +14,7 @@ ttyUL0
 ttyUL1
 ttyUL2
 ttyUL3
+ttyPSC0
+ttyPSC1
+ttyPSC2
+ttyPSC3