ARM: 8684/1: NOMMU: Remove unused KTHREAD_SIZE definition

I didn't find any use of this macro in the current kernel tree (with git
grep). KTHREAD_SIZE is no longer used for a very very long time. So
let's remove this definition.
Signed-off-by: NJérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Reviewed-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

arch/arm/include/asm/page-nommu.h

@@ -11,12 +11,6 @@
 #ifndef _ASMARM_PAGE_NOMMU_H
 #define _ASMARM_PAGE_NOMMU_H
 
-#if !defined(CONFIG_SMALL_TASKS) && PAGE_SHIFT < 13
-#define KTHREAD_SIZE (8192)
-#else
-#define KTHREAD_SIZE PAGE_SIZE
-#endif
- 
 #define clear_page(page)	memset((page), 0, PAGE_SIZE)
 #define copy_page(to,from)	memcpy((to), (from), PAGE_SIZE)