arm64: a37xx: pinctrl: Fix PWM pins indexes

Commit 5534fb4f ("arm64: a37xx: pinctrl: Correct PWM pins
definitions") introduced bogus definitions os PWM pins: all 4 pins have
index 11, instead of having indexes 11, 12, 13, 14.

Fix this.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>