tbbr-cot: fix the issue of compiling time define

Incorrect value is picked for TF_MBEDTLS_USE_RSA defination,
even if the TF_MBEDTLS_RSA is enabled.

Due to which PK_DER_LEN is defined incorrectly.
Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Change-Id: I2ca4ca121e0287b88ea689c885ddcd45a34a3e91

include/common/tbbr/cot_def.h

@@ -7,6 +7,10 @@
 #ifndef COT_DEF_H
 #define COT_DEF_H
 
+#ifdef MBEDTLS_CONFIG_FILE
+#include MBEDTLS_CONFIG_FILE
+#endif
+
 /* TBBR CoT definitions */
 #if defined(SPD_spmd)
 #define COT_MAX_VERIFIED_PARAMS		8