configs: stm32: update SRAM address for STM32H7 disco and eval

configs: stm32: update SRAM address for STM32H7 disco and eval

As suggested by Vikas Manocha, update embedded SRAM address
to use AXI SRAM available on D1 domain instead of using
AHB SRAM (D2 domain).
On some STM32H743 SoCs, D2 domain SRAM is accessible even if
SRAMxEN bit in AHB2ENR bits are not set whereas on others SoCs
version it's not accessible.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Vikas Manocha <vikas.manocha@st.com>