dts/arm/st: add additional g0 device defintions

Restructures dts files(value line definitions are no longer included by
others), and adds additional devices(g05x and g0bx).
All newly added timer pwm prescalers are set to 0.
lpuart1 is moved from stm32g0.dtsi to stm32g031.dtsi, as it is not
available on stm32g0x0 soc.

Signed-off-by: Thomas Stranger <thomas.stranger@outlook.com>