MIPS: SGI-IP30: Move irq bits to better header files

Move HEART specific parts of mach-ip30/irq.h to asm/sgi/heart.h and IP30
specific parts to sgi-ip30/ip30-common.h.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: add support for SGI Octane (IP30)

This changeset adds support for SGI Octane/Octane2 workstations.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org