irqchip: Fix kernel-doc parameter typo for IRQCHIP_DECLARE

The documentation refers to "compstr" when we have the parameter named
"compat", fix the typo.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211020184859.2705451-14-f.fainelli@gmail.com