ppc4xx: Use common NS16550 driver for PPC4xx UART

This patch removes the PPC4xx UART driver. Instead the common NS16550
driver is used, since all PPC4xx SoC's use this peripheral device.

The file 4xx_uart.c now only implements the UART clock calculation
function which also sets the SoC internal UART divisors.

All PPC4xx board config headers are changed to use this common NS16550
driver now.

Tested on these boards:
acadia, canyonlands, katmai, kilauea, sequoia, zeus

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/include/configs/redwood.h b/include/configs/redwood.h
index 4b744a7..913db94 100644
--- a/include/configs/redwood.h
+++ b/include/configs/redwood.h
@@ -47,7 +47,6 @@
  * actual resources get mapped (not physical addresses)
  *----------------------------------------------------------------------*/
 #define CONFIG_SYS_FLASH_BASE		0xfff00000	/* start of FLASH	*/
-#define CONFIG_SYS_PERIPHERAL_BASE	0xa0000000	/* internal peripherals	*/
 #define CONFIG_SYS_ISRAM_BASE		0x90000000	/* internal SRAM	*/
 
 #define CONFIG_SYS_PCI_BASE		0xd0000000	/* internal PCI regs	*/
@@ -77,6 +76,11 @@
 #define CONFIG_SYS_FPGA_BASE		0xe2000000	/* epld			*/
 #define CONFIG_SYS_OPER_FLASH		0xe7000000	/* SRAM - OPER Flash	*/
 
+/*
+ * Serial Port
+ */
+#define CONFIG_CONS_INDEX	1	/* Use UART0			*/
+
 /*-----------------------------------------------------------------------
  * Initial RAM & stack pointer (placed in internal SRAM)
  *----------------------------------------------------------------------*/