t0lte/m3 add LTE dts data

This splits the n710x-$panel dts files into ones for n7100 and n7105, and includes a dtsi with LTE modem nodes in the n7105 ones, and the i9305 one too, as the pins are the same.

Also, a couple of modem hardware IDs are added to the qcserial driver in preparation for modem bringup. This driver will be built as a module, so won't increase kernel size.

This will make it easier to bring up modem using userspace tool gpioset and a firmware loading tool, though the latter needs some work.