mxc: add arch_reset() function

This patch adds arch_reset() function for all mxc platforms.

It also removes (unsused) arch/arm/mach-mx2/system.c file.

This patch has been tested on i.MX1/27/31/35

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx2/Makefile b/arch/arm/mach-mx2/Makefile
index 6e1a2bf..950649a 100644
--- a/arch/arm/mach-mx2/Makefile
+++ b/arch/arm/mach-mx2/Makefile
@@ -4,7 +4,7 @@
 
 # Object file lists.
 
-obj-y	:=  system.o generic.o devices.o serial.o
+obj-y	:=  generic.o devices.o serial.o
 
 obj-$(CONFIG_MACH_MX21) += clock_imx21.o