irqchip/irq-bcm7038-l1: Allow building on ARM 32-bit

We need to have a definition for cpu_logical_map[] which on ARM
platforms is provided by asm/smp_plat.h. This header is not
automatically included from linux/smp.h and untangling it is a bit
difficult.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200709234141.4901-1-f.fainelli@gmail.com