at91: introduce commom AT91_BASE_SYS

On all at91 except rm9200 and x40 have the System Controller starts
at address 0xffffc000 and has a size of 16KiB.

On rm9200 it's start at 0xfffe4000 of 111KiB with non reserved data starting
at 0xfffff000

This patch removes the individual definitions of AT91_BASE_SYS and
replaces them with a common version at base 0xfffffc000 and size 16KiB
and map the same memory space

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>

arch/arm/mach-at91/board-csb637.c

@@ -43,7 +43,7 @@
 static void __init csb637_init_early(void)
 {
 	/* Initialize processor: 3.6864 MHz crystal */
-	at91rm9200_initialize(3686400);
+	at91_initialize(3686400);
 
 	/* DBGU on ttyS0. (Rx & Tx only) */
 	at91_register_uart(0, 0, 0);
@@ -139,7 +139,7 @@ static void __init csb637_board_init(void)
 MACHINE_START(CSB637, "Cogent CSB637")
 	/* Maintainer: Bill Gatliff */
 	.timer		= &at91rm9200_timer,
-	.map_io		= at91rm9200_map_io,
+	.map_io		= at91_map_io,
 	.init_early	= csb637_init_early,
 	.init_irq	= csb637_init_irq,
 	.init_machine	= csb637_board_init,