boards: nxp: frdm_k32l2b3: Add initial support

Adding initial support for NXP FRDM K32L2B3 board.

Signed-off-by: Ishraq Ibne Ashraf <ishraq.i.ashraf@gmail.com>

dts: arm: nxp: Fix SRAM node name

Fix address part of the SRAM node name.
Change the SRAM start address definition to lower
case hexadecimal to be consistent.

Signed-off-by: Ishraq Ibne Ashraf <ishraq.i.ashraf@gmail.com>