Fix rsa acceleration exponent issue, turn back on.

Author: twcook86

wolfcrypt/src/port/nxp/casper_port.c

@@ -56,7 +56,7 @@ int casper_rsa_public_exptmod(
     int res;
     int sig_sz = inLen;
     int key_sz = mp_unsigned_bin_size(&key->n);
-    word32 exp;
+    word32 exp = 0;
 
     if (inLen > CASPER_MAX_BUF_SZ || *outLen > CASPER_MAX_BUF_SZ)
         return BAD_FUNC_ARG;

wolfssl/wolfcrypt/settings.h

@@ -2135,6 +2135,7 @@ extern void uITRON4_free(void *p) ;
     #define WOLFSSL_NXP_HASHCRYPT_SHA
     #define WOLFSSL_NXP_HASHCRYPT_SHA256
     #define WOLFSSL_NXP_CASPER
+    #define WOLFSSL_NXP_CASPER_RSA_PUB_EXPTMOD
 #elif defined(WOLFSSL_NXP_LPC55S69_NO_HWACCEL)
     #define WOLFSSL_NXP_RNG_1
 #endif