boards: stm32: argonkey: Add dts support to sensors

This patch adds dts support to lps22hb/hts221/vl53l0x
I2C sensors as well as lsm6dsl SPI sensor.

Since some info, like gpio for irq triggering or SPI bus
characteristics, may be provided through dts, they need
to be made optional in the LSM6DSL driver by usage of
macros like HAS_DTS_SPI_PINS or HAS_DTS_SPI_DEVICE.

Signed-off-by: Armando Visconti <armando.visconti@st.com>