build: add build config for Versal NET

Add build configuration for AMD Versal NET platform to tftf.
The default configuration builds for Versal tests(TESTS=versal),
which includes standard tests along with AMD specific tests cases.

Signed-off-by: Akshay Belsare <akshay.belsare@amd.com>
Change-Id: I968dce614a508ae08e93c2b17a77e04c27b06b23
diff --git a/tftf_config/versal_net-default b/tftf_config/versal_net-default
new file mode 100644
index 0000000..f5c5616
--- /dev/null
+++ b/tftf_config/versal_net-default
@@ -0,0 +1,3 @@
+CROSS_COMPILE=aarch64-none-elf-
+PLAT=versal_net
+TESTS=versal