dts: arm: stm32f373x soc has 2 dma instances of same type.

Like the first instance of the dma in the stm32l3xx soc,
the second DMA instance of the stm32f373 is of the same type
V2bis (dma  request is fixed (no dma-slot).
The dma-cell has channel and config.

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