sh: Kill off machvec IRQ hinting.

Everything is using sparseirq these days, so we have no need to
arbitrarily size nr_irqs ahead of time. The legacy IRQ pre-allocation
likewise has no meaning for us, so that's killed off too. We now depend
on nr_irqs expansion by the generic hardirq layer instead.

It's also worth noting that the majority of boards had completely bogus
values for their nr_irqs relative to their CPU and configurations, so
this ends up correcting behaviour for quite a few platforms.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/boards/mach-lboxre2/setup.c

@@ -79,6 +79,5 @@ device_initcall(lboxre2_devices_setup);
  */
 static struct sh_machine_vector mv_lboxre2 __initmv = {
 	.mv_name		= "L-BOX RE2",
-	.mv_nr_irqs		= 72,
 	.mv_init_irq		= init_lboxre2_IRQ,
 };