[MIPS] Lasat: bring back from the dead

After the common MIPS CPU interrupt controller (for irq0-7) was introduced
the Lasat boards didn't get their interrupts right, so nothing worked. The
old routines need to be offset by the new 8 hardware interrupts common to
all MIPS CPU's.

Signed-off-by: Thomas Horsten <thomas@horsten.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>