net: disable MBEDTLS in SPL

Building SPL fails with MBEDTLS enabled.
Currently we don't need it there.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
diff --git a/lib/sha512.c b/lib/sha512.c
index ea555ff..0e75c1a 100644
--- a/lib/sha512.c
+++ b/lib/sha512.c
@@ -288,7 +288,8 @@
 		unsigned char *output, unsigned int chunk_sz)
 {
 	sha512_context ctx;
-#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+#if !defined(USE_HOSTCC) && \
+    (defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG))
 	const unsigned char *end;
 	unsigned char *curr;
 	int chunk;
@@ -296,7 +297,8 @@
 
 	sha384_starts(&ctx);
 
-#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+#if !defined(USE_HOSTCC) && \
+    (defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG))
 	curr = (unsigned char *)input;
 	end = input + ilen;
 	while (curr < end) {
@@ -351,7 +353,8 @@
 		unsigned char *output, unsigned int chunk_sz)
 {
 	sha512_context ctx;
-#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+#if !defined(USE_HOSTCC) && \
+    (defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG))
 	const unsigned char *end;
 	unsigned char *curr;
 	int chunk;
@@ -359,7 +362,8 @@
 
 	sha512_starts(&ctx);
 
-#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+#if !defined(USE_HOSTCC) && \
+    (defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG))
 	curr = (unsigned char *)input;
 	end = input + ilen;
 	while (curr < end) {