[SPARC32]: Add irqflags.h to sparc32 and use it from generic code.

Added asm-sparc/irqflags.h and moved irq related code from system.h to it.
Renamed local_irq functions to raw_local_irq in irq.c.
Modified system.h to include linux/irqflags.h which includes asm/irqflags.h.
Added TRACE_IRQFLAGS_SUPPORT to Kconfig.debug.

This is the first step in adding IRQ-flags state tracing as outlined in
Documentation/irqflags-tracing.txt.  These changes should be harmless
because they just move things around and rename them.

The next step is making the lowlevel entry code modifications which
to be honest are beyond my capabilities at this point.

Boot tested on an ss20 running an SMP kernel.

Signed-off-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>