[ARM] Cleanup ARM includes

arch/arm/kernel/entry-armv.S has contained a comment suggesting
that asm/hardware.h and asm/arch/irqs.h should be moved into the
asm/arch/entry-macro.S include.  So move the includes to these
two files as required.

Add missing includes (asm/hardware.h, asm/io.h) to asm/arch/system.h
includes which use those facilities, and remove asm/io.h from
kernel/process.c.

Remove other unnecessary includes from arch/arm/kernel, arch/arm/mm
and arch/arm/mach-footbridge.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/arch-clps711x/system.h b/include/asm-arm/arch-clps711x/system.h
index 2ab981f..11e1491 100644
--- a/include/asm-arm/arch-clps711x/system.h
+++ b/include/asm-arm/arch-clps711x/system.h
@@ -20,7 +20,9 @@
 #ifndef __ASM_ARCH_SYSTEM_H
 #define __ASM_ARCH_SYSTEM_H
 
+#include <asm/hardware.h>
 #include <asm/hardware/clps7111.h>
+#include <asm/io.h>
 
 static inline void arch_idle(void)
 {