[POWERPC] Provide dummy hard_irq_enable/disable() for PPC32

To allow arch/powerpc/kernel/crash.c to build on 32-bit we need a
definition of hard_irq_disable(). 32-bit doesn't support the lazy
interrupt disabling mechanism, so on 32-bit hard_irq_disable() is
simply local_irq_disable(). Add a definition for hard_irq_enable()
just for completeness.

This allows (KEXEC=y && PPC32=y) to build again. Broken since
d04c56f.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-powerpc/hw_irq.h

@@ -102,6 +102,9 @@ static inline void local_irq_save_ptr(unsigned long *flags)
 #define local_irq_save(flags)	local_irq_save_ptr(&flags)
 #define irqs_disabled()		((mfmsr() & MSR_EE) == 0)
 
+#define hard_irq_enable()	local_irq_enable()
+#define hard_irq_disable()	local_irq_disable()
+
 #endif /* CONFIG_PPC64 */
 
 #define mask_irq(irq)						\