ARM: dts: imx6ul: fix PWM[1-4] interrupts

According to the i.MX6UL/L RM, table 3.1 "ARM Cortex A7 domain interrupt
summary", the interrupts for the PWM[1-4] go from 83 to 86.

Fixes: b9901fe8 ("ARM: dts: imx6ul: add pwm[1-4] nodes")
Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>