MIPS: GIC: Move GIC_LOCAL_INT_* to asm/mips-gic.h

MIPS: GIC: Move GIC_LOCAL_INT_* to asm/mips-gic.h

Move the definition of VP-local interrupts provided by the MIPS Global
Interrupt Controller to the new asm/mips-gic.h header to be alongside
the new accessor functions. Whilst at it, convert to an enum which lends
itself more easily to expansion & documentation.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17037/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>