avr32: make architecture sys_clone prototype match asm-generic prototype

This patch will fix the arguments to the architecture sys_clone() function to
match the asm-generic/syscalls.h prototype. In the same go remove the
architecture specific prototype for the same function.

The sys_clone() function is only called from assembly, hence the argument types
were not having any affect.

Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>

arch/avr32/include/asm/syscalls.h

@@ -15,11 +15,6 @@
 #include <linux/types.h>
 #include <linux/signal.h>
 
-/* kernel/process.c */
-asmlinkage int sys_clone(unsigned long, unsigned long,
-			 unsigned long, unsigned long,
-			 struct pt_regs *);
-
 /* mm/cache.c */
 asmlinkage int sys_cacheflush(int, void __user *, size_t);