MN10300: Save frame pointer in thread_info struct rather than global var

Save the current exception frame pointer in the thread_info struct rather than
in a global variable as the latter makes SMP tricky, especially when preemption
is also enabled.

This also replaces __frame with current_frame() and rearranges header file
inclusions to make it all compile.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
diff --git a/arch/mn10300/include/asm/irq_regs.h b/arch/mn10300/include/asm/irq_regs.h
index a848cd2..97d0cb5 100644
--- a/arch/mn10300/include/asm/irq_regs.h
+++ b/arch/mn10300/include/asm/irq_regs.h
@@ -18,7 +18,11 @@
 #define ARCH_HAS_OWN_IRQ_REGS
 
 #ifndef __ASSEMBLY__
-#define get_irq_regs() (__frame)
+static inline __attribute__((const))
+struct pt_regs *get_irq_regs(void)
+{
+	return current_frame();
+}
 #endif
 
 #endif /* _ASM_IRQ_REGS_H */