Remove unused configs

Removed unused configs as proper configurations are already added
as below to run in CI:
1. fvp-tbb-mbedtls-romlib-cot-in-dtb,fvp-default:fvp-tftf-fip.tftf-aemv8a-debug
2. fvp-tbb-mbedtls-romlib-cot-in-dtb

Change-Id: I6aefbf4cb2f28a457382dc9908c65936a6ea52a8
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>