ARM: OMAP2+: board-generic: Remove stale of_irq macros

When commit c4082d49 ("ARM: omap2+: board-generic: clean up the
irq data from board file") cleaned up the direct usage of gic_of_init
and omap_intc_of_init, it failed to clean up the macros properly.

Since these macros are no longer used, lets just remove them.

Fixes: c4082d49

 ("ARM: omap2+: board-generic: clean up the irq data from board file")
Reported-by: Carlos Hernandez <ceh@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>