psa: Enable use of PSA examples with CHECK_PARAMS

When MBEDTLS_CHECK_PARAMS is enabled, it's required to have an
implementation of mbedtls_param_failed() present. Without it in the PSA
examples, building the PSA examples will result in linker errors like
the following.

  ../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_import':
  rsa.c:(.text+0x9fd): undefined reference to `mbedtls_param_failed'
  ../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_import_raw':
  rsa.c:(.text+0xb0b): undefined reference to `mbedtls_param_failed'
  ../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_complete':
  rsa.c:(.text+0xe63): undefined reference to `mbedtls_param_failed'
  ../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_export_raw':
  rsa.c:(.text+0xfee): undefined reference to `mbedtls_param_failed'
  ../../library/libmbedcrypto.a(rsa.c.o): In function `mbedtls_rsa_export':
  rsa.c:(.text+0x116f): undefined reference to `mbedtls_param_failed'
  ../../library/libmbedcrypto.a(rsa.c.o):rsa.c:(.text+0x1304): more undefined
  references to `mbedtls_param_failed' follow
  collect2: error: ld returned 1 exit status
  programs/psa/CMakeFiles/crypto_examples.dir/build.make:97: recipe for target
  'programs/psa/crypto_examples' failed
  make[2]: *** [programs/psa/crypto_examples] Error 1

Add an implementation of mbedtls_param_failed() to the PSA Crypto
examples to avoid getting this error on the PSA examples.

programs/psa/crypto_examples.c

@@ -324,6 +324,18 @@ static void cipher_examples( void )
         mbedtls_printf( "\tsuccess!\r\n" );
 }
 
+#if defined(MBEDTLS_CHECK_PARAMS)
+#include "mbedtls/platform_util.h"
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
 int main( void )
 {
     ASSERT( psa_crypto_init( ) == PSA_SUCCESS );

programs/psa/key_ladder_demo.c

@@ -618,6 +618,18 @@ static void usage( void )
     mbedtls_printf( "                    and the same sequence of labels.\n" );
 }
 
+#if defined(MBEDTLS_CHECK_PARAMS)
+#include "mbedtls/platform_util.h"
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
 int main( int argc, char *argv[] )
 {
     const char *key_file_name = "master.key";