warp7: Print out the OPTEE DRAM region

Right now a region of 0x300000 bytes is allocated at the end of DRAM for
the purposes of loading an OPTEE firmware inside of it. This patch adds the
printout of the relevant address ranges.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Tested-by: Breno Lima <breno.lima@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>