arm: fix compile failure in orion5x/dns323-setup.c

Upstream commit d5341942d784134f2997b3ff82cd63cf71d1f932 "PCI: Make the
struct pci_dev * argument of pci_fixup_irqs const." leaked an extra
"const" into an actual call site (vs a proto/decl) which causes this:

arch/arm/mach-orion5x/dns323-setup.c: In function 'dns323_pci_map_irq':
arch/arm/mach-orion5x/dns323-setup.c:80: error: expected expression before 'const'
arch/arm/mach-orion5x/dns323-setup.c:80: error: too few arguments to function 'orion5x_pci_map_irq'
make[3]: *** [arch/arm/mach-orion5x/dns323-setup.o] Error 1

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Ralf Baechle <ralf@linux-mips.org>