parisc: Fix implicit declaration of function '__kernel_text_address'

Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/arch/parisc/kernel/stacktrace.c b/arch/parisc/kernel/stacktrace.c
index 6b4ca91..023834e 100644
--- a/arch/parisc/kernel/stacktrace.c
+++ b/arch/parisc/kernel/stacktrace.c
@@ -8,6 +8,7 @@
  *
  *  TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
  */
+#include <linux/kernel.h>
 #include <linux/stacktrace.h>
 
 #include <asm/unwind.h>