Fix SHA definitions and their dependencies in library and test suites.

Rework SHA224 and SHA283 documentation.
Define MBEDTLS_SHAxxx_C options in alphabetic order.
Fix SHA224 and SHA384 dependencies in test suites.

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
diff --git a/library/ssl_cookie.c b/library/ssl_cookie.c
index 22484f7..ee2085d 100644
--- a/library/ssl_cookie.c
+++ b/library/ssl_cookie.c
@@ -48,7 +48,7 @@
 #define COOKIE_MD           MBEDTLS_MD_SHA224
 #define COOKIE_MD_OUTLEN    32
 #define COOKIE_HMAC_LEN     28
-#elif defined(MBEDTLS_SHA512_C)
+#elif defined(MBEDTLS_SHA384_C)
 #define COOKIE_MD           MBEDTLS_MD_SHA384
 #define COOKIE_MD_OUTLEN    48
 #define COOKIE_HMAC_LEN     28