Capitalise MPS trace macros

Capitalise the MPS trace macros, as per the coding style (and make a slight
change to naming convention to avoid a name collision).

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/mps_common.h b/library/mps_common.h
index dd6e31b..d20776f 100644
--- a/library/mps_common.h
+++ b/library/mps_common.h
@@ -104,7 +104,7 @@
     {                                                                          \
         if( !(cond) )                                                          \
         {                                                                      \
-            MBEDTLS_MPS_TRACE( mbedtls_mps_trace_error, string );              \
+            MBEDTLS_MPS_TRACE( MBEDTLS_MPS_TRACE_TYPE_ERROR, string );         \
             MBEDTLS_MPS_TRACE_RETURN( MBEDTLS_ERR_MPS_OPERATION_UNEXPECTED );  \
         }                                                                      \
     } while( 0 )
@@ -126,7 +126,7 @@
     {                                                                   \
         if( !(cond) )                                                   \
         {                                                               \
-            MBEDTLS_MPS_TRACE( mbedtls_mps_trace_error, string );       \
+            MBEDTLS_MPS_TRACE( MBEDTLS_MPS_TRACE_TYPE_ERROR, string );  \
             MBEDTLS_MPS_TRACE_RETURN( MBEDTLS_ERR_MPS_INTERNAL_ERROR ); \
         }                                                               \
     } while( 0 )