Add ril v2 support.

Change-Id: I14f4d5f3650f0d397c38a72e8bea2600c17b07de
diff --git a/mbtk/mbtk_rild_v2/src/atchannel.c b/mbtk/mbtk_rild_v2/src/atchannel.c
index bf0384c..316e62a 100755
--- a/mbtk/mbtk_rild_v2/src/atchannel.c
+++ b/mbtk/mbtk_rild_v2/src/atchannel.c
@@ -36,7 +36,7 @@
 #define MAX_AT_RESPONSE (8 * 1024)
 #define HANDSHAKE_RETRY_COUNT 20
 #define HANDSHAKE_TIMEOUT_MSEC 500
-#define AT_BUFF_MAX 100
+#define AT_BUFF_MAX 1024
 
 static pthread_t s_tid_reader;
 static int s_at_fd = -1;    /* fd of the AT channel */