dts: arm: stm32f0 soc serie has dma of type V2bis

The type of DMA for the stm32f0 devices was wrong
Its DMA is of type V2bis where the peripheral request is fixed.
The corresponding DMA cell has 2 elements.
The stm32f091 has two DMA instances.

Signed-off-by: Francois Ramu <francois.ramu@st.com>