build: add build config for rdn2cfg3 in tf and tftf

Add tf and tftf build configs for infra-rd platform rdn2cfg3

Signed-off-by: Tony K Nadackal <tony.nadackal@arm.com>
Change-Id: I483886898920ebd74d5003661528479b0ae2c2fc
diff --git a/tf_config/fvp-rdn2cfg3-tbb b/tf_config/fvp-rdn2cfg3-tbb
new file mode 100644
index 0000000..27c2809
--- /dev/null
+++ b/tf_config/fvp-rdn2cfg3-tbb
@@ -0,0 +1,8 @@
+ARM_ROTPK_LOCATION=devel_rsa
+CREATE_KEYS=1
+CROSS_COMPILE=aarch64-none-elf-
+CSS_SGI_PLATFORM_VARIANT=3
+GENERATE_COT=1
+PLAT=rdn2
+ROT_KEY=plat/arm/board/common/rotpk/arm_rotprivk_rsa.pem
+TRUSTED_BOARD_BOOT=1