Remove an unnecessary #else and commented line
With the else branch commented out, both lines are unnecessary.  We
could check for the invalid configuration in the future, once tests were
made to exclude this combination.
@@ -352,8 +352,6 @@ extern "C" {
#if defined(PSA_WANT_KEY_TYPE_CHACHA20)
#define MBEDTLS_CHACHAPOLY_C
#define MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 1
-#else /* not PSA_WANT_KEY_TYPE_CHACHA20 */
-// #error "PSA_WANT_ALG_CHACHA20_POLY1305 requires PSA_WANT_KEY_TYPE_CHACHA20"
#endif /* PSA_WANT_KEY_TYPE_CHACHA20 */
#endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
