ppc64: defconfig update

arch/ppc64/defconfig

@@ -487,10 +487,26 @@ CONFIG_VIOPATH=y
 #
 CONFIG_VT=y
 CONFIG_VT_CONSOLE=y
-CONFIG_SERIAL=y
-CONFIG_SERIAL_CONSOLE=y
-# CONFIG_SERIAL_EXTENDED is not set
 # CONFIG_SERIAL_NONSTANDARD is not set
+
+#
+# Serial drivers
+#
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+# CONFIG_SERIAL_8250_CS is not set
+# CONFIG_SERIAL_8250_EXTENDED is not set
+# CONFIG_SERIAL_8250_MANY_PORTS is not set
+# CONFIG_SERIAL_8250_SHARE_IRQ is not set
+# CONFIG_SERIAL_8250_DETECT_IRQ is not set
+# CONFIG_SERIAL_8250_MULTIPORT is not set
+# CONFIG_SERIAL_8250_RSA is not set
+
+#
+# Non-8250 serial port support
+#
+CONFIG_SERIAL_CORE=y
+CONFIG_SERIAL_CORE_CONSOLE=y
 CONFIG_UNIX98_PTYS=y
 CONFIG_UNIX98_PTY_COUNT=256
 CONFIG_HVC_CONSOLE=y