drivers: timer: make lptim depend on the dt node

The stm32_lptim driver is hardcoded to use lptim1.

Make the Kconfig option depend on the presence of the node label in the
devicetree, so that there's one less list of supported SoC to keep track
of.

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
1 file changed