refactor: mbedtls: Remove redundant MBEDTLS_CONFIG_FILE

MBEDTLS_CONFIG_FILE is chosen when MBEDTLS_DIR is specified,
adding a redundant MBEDTLS_CONFIG_FILE name can cause
problem when we rename a config file or have more
than one config file.

Change-Id: I8bc6c27547e78a3506036b46bd9e12c8665a7147
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
(cherry picked from commit 8841f11a8ad466f9a1454c800a4a67b920e6f24e)
2 files changed