feat(versal-net): add build config for Xilinx Versal NET SoC

Add build config for Xilinx Versal NET SoC.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Change-Id: I2f2d6994bb67163c480c7d9de1cdd440f894b569
diff --git a/tf_config/versal_net-default b/tf_config/versal_net-default
new file mode 100644
index 0000000..152a90a
--- /dev/null
+++ b/tf_config/versal_net-default
@@ -0,0 +1,3 @@
+CROSS_COMPILE=aarch64-none-elf-
+PLAT=versal_net
+RESET_TO_BL31=1