refactor(plat/qemu): increase the non-secure DRAM size

In the qemu memory map 1GB and up is RAM. Change the
size of NS DRAM to 3GB to support VM's with more
memory requirements.

Signed-off-by: Ruchika Gupta <ruchika.gupta@linaro.org>
Change-Id: If15cf3b9d3e2e7876c40ce888f22e887893fe696
1 file changed