microblaze: Fix missing microblaze specific syscalls declaration

Warning log:
CHECK   arch/microblaze/kernel/sys_microblaze.c
arch/microblaze/kernel/sys_microblaze.c:37:17: warning: symbol 'microblaze_vfork' was not declared. Should it be static?
arch/microblaze/kernel/sys_microblaze.c:43:17: warning: symbol 'microblaze_clone' was not declared. Should it be static?
arch/microblaze/kernel/sys_microblaze.c:50:17: warning: symbol 'microblaze_execve' was not declared. Should it be static?
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/syscalls.h

 #ifndef __ASM_MICROBLAZE_SYSCALLS_H
 
+asmlinkage long microblaze_vfork(struct pt_regs *regs);
+asmlinkage long microblaze_clone(int flags, unsigned long stack,
+							struct pt_regs *regs);
+asmlinkage long microblaze_execve(const char __user *filenamei,
+				  const char __user *const __user *argv,
+				  const char __user *const __user *envp,
+				  struct pt_regs *regs);
+
 asmlinkage long sys_clone(int flags, unsigned long stack, struct pt_regs *regs);
 #define sys_clone sys_clone
 

arch/microblaze/kernel/sys_microblaze.c

@@ -40,7 +40,8 @@ asmlinkage long microblaze_vfork(struct pt_regs *regs)
 						regs, 0, NULL, NULL);
 }
 
-asmlinkage long microblaze_clone(int flags, unsigned long stack, struct pt_regs *regs)
+asmlinkage long microblaze_clone(int flags, unsigned long stack,
+							struct pt_regs *regs)
 {
 	if (!stack)
 		stack = regs->r1;