MIPS: PCI: pci-bcm1480: Include missing vt.h header

It's needed for the MAX_NR_CONSOLES macro.

Fixes the following build problem on a randconfig:

arch/mips/pci/pci-bcm1480.c: In function 'bcm1480_pcibios_init':
arch/mips/pci/pci-bcm1480.c:261:36: error: 'MAX_NR_CONSOLES'
undeclared (first use in this function)
arch/mips/pci/pci-bcm1480.c:261:36: note: each undeclared
identifier is reported only once for each function it appears in
make[1]: *** [arch/mips/pci/pci-bcm1480.o] Error 1

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5858/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>