gpio: davinci: Validate the obtained number of IRQs

[ Upstream commit 7aa9b96e ]

Value of pdata->gpio_unbanked is taken from Device Tree. In case of broken
DT due to any error this value can be any. Without this value validation
there can be out of chips->irqs array boundaries access in
davinci_gpio_probe().

Validate the obtained nirq value so that it won't exceed the maximum
number of IRQs per bank.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: eb3744a2

 ("gpio: davinci: Do not assume continuous IRQ numbering")
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Link: https://lore.kernel.org/r/20240618144344.16943-1-amishin@t-argos.ru
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>