irqchip/davinci: Remove leftover header

Commit fa8dede4 ("irqchip: remove davinci aintc driver") removed the
davinci aintc driver but left behind the associated header. Remove it
now.

Fixes: fa8dede4 ("irqchip: remove davinci aintc driver")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/all/20250306084552.15894-1-brgl@bgdev.pl