sparc32: fix sparse warnings in windows.c

Fix following warnings:
windows.c:16:6: warning: symbol 'flush_user_windows' was not declared. Should it be static?
windows.c:109:6: warning: symbol 'try_to_clear_window_buffer' was not declared. Should it be static?

Add missing include of cacheflush.h + add declaration of try_to_clear_window_buffer in kernel.h

Signed-off-by: Sam Ravnborg <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/sparc/kernel/kernel.h

···
 asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
                                struct sigstack __user *ossptr,
                                unsigned long sp);
+
+/* windows.c */
+void try_to_clear_window_buffer(struct pt_regs *regs, int who);
+
 #else /* CONFIG_SPARC32 */
 #endif /* CONFIG_SPARC32 */
 #endif /* !(__SPARC_KERNEL_H) */

arch/sparc/kernel/windows.c

···
 #include <linux/mm.h>
 #include <linux/smp.h>
 
+#include <asm/cacheflush.h>
 #include <asm/uaccess.h>
+
+#include "kernel.h"
 
 /* Do save's until all user register windows are out of the cpu. */
 void flush_user_windows(void)