WP76 UART2 uses different tty device since Firmware R12

Hi,

I’ve been using WP76 Firmware R9 for a while.
It contains Linux version is 3.18.44 and the UARTs are coupled to ttyHS0 and ttyHSL1.

When I upgrade towards Firmware R12, I see that the Linux version is 3.18.122,
and the UARTs are coupled to ttyHS0 and ttyHS1.

I assume that this change is related to the changes in the Yocto sources:
/kernel/arch/arm/boot/dts/qcom/mdm9607-wp76xx.dtsi
/kernel/arch/arm/boot/dts/qcom/mdm9607-swi.dtsi

What is the reason behind this change?

Greetings,

annaertd