Replace MBEDTLS_MD_CAN_SHA256 with PSA_WANT_ALG_SHA_256

Signed-off-by: Elena Uziunaite <elena.uziunaite@arm.com>
diff --git a/programs/pkey/rsa_sign.c b/programs/pkey/rsa_sign.c
index e14953b..0e32e13 100644
--- a/programs/pkey/rsa_sign.c
+++ b/programs/pkey/rsa_sign.c
@@ -12,13 +12,13 @@
 #include "mbedtls/md.h"
 
 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) ||  \
-    !defined(MBEDTLS_MD_CAN_SHA256) || !defined(MBEDTLS_MD_C) || \
+    !defined(PSA_WANT_ALG_SHA_256) || !defined(MBEDTLS_MD_C) || \
     !defined(MBEDTLS_FS_IO)
 int main(void)
 {
     mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or "
                    "MBEDTLS_MD_C and/or "
-                   "MBEDTLS_MD_CAN_SHA256 and/or MBEDTLS_FS_IO not defined.\n");
+                   "PSA_WANT_ALG_SHA_256 and/or MBEDTLS_FS_IO not defined.\n");
     mbedtls_exit(0);
 }
 #else
@@ -151,5 +151,5 @@
 
     mbedtls_exit(exit_code);
 }
-#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && MBEDTLS_MD_CAN_SHA256 &&
+#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && PSA_WANT_ALG_SHA_256 &&
           MBEDTLS_FS_IO */