pinctrl: single: Use a separate lockdep class

The single pinmux controller can be cascaded to the other interrupt
controllers. Hence when propagating wake-up settings to its parent
interrupt controller, there's possiblity of detecting possible recursive
locking and getting lockdep warning.

This patch avoids this false positive by using a separate lockdep class
for this single pinctrl interrupts.

Cc: linux-gpio@vger.kernel.org
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>