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-pcontrol-g20.c b/arch/arm/mach-at91/board-pcontrol-g20.c
index 21a21af..7651e7f 100644
--- a/arch/arm/mach-at91/board-pcontrol-g20.c
+++ b/arch/arm/mach-at91/board-pcontrol-g20.c
@@ -223,7 +223,7 @@
 MACHINE_START(PCONTROL_G20, "PControl G20")
 	/* Maintainer: pgsellmann@portner-elektronik.at */
 	.timer		= &at91sam926x_timer,
-	.map_io		= at91sam9260_map_io,
+	.map_io		= at91_map_io,
 	.init_early	= pcontrol_g20_init_early,
 	.init_irq	= init_irq,
 	.init_machine	= pcontrol_g20_board_init,