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>
diff --git a/arch/arm/mach-at91/board-eco920.c b/arch/arm/mach-at91/board-eco920.c
index bfc0062..8639fbd 100644
--- a/arch/arm/mach-at91/board-eco920.c
+++ b/arch/arm/mach-at91/board-eco920.c
@@ -35,7 +35,7 @@
 	/* Set cpu type: PQFP */
 	at91rm9200_set_type(ARCH_REVISON_9200_PQFP);
 
-	at91rm9200_initialize(18432000);
+	at91_initialize(18432000);
 
 	/* Setup the LEDs */
 	at91_init_leds(AT91_PIN_PB0, AT91_PIN_PB1);
@@ -135,7 +135,7 @@
 MACHINE_START(ECO920, "eco920")
 	/* Maintainer: Sascha Hauer */
 	.timer		= &at91rm9200_timer,
-	.map_io		= at91rm9200_map_io,
+	.map_io		= at91_map_io,
 	.init_early	= eco920_init_early,
 	.init_irq	= eco920_init_irq,
 	.init_machine	= eco920_board_init,