In order to allow the GICv4 code to link properly on 32bit ARM,
make sure we don't use 64bit divisions when it isn't strictly
necessary.

Fixes: 4e6437f1 ("irqchip/gic-v4.1: Ensure L2 vPE table is allocated at RD level")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>