diag: Add UART support

DIAG traffic has been supported over USB and SD card. This
change adds capability to route DIAG traffic over UART.

Change-Id: I0d6732fcbb19950700218140d581b5759e676b74
Signed-off-by: Shalabh Jain <shalabhj@codeaurora.org>
diff --git a/drivers/char/diag/diagfwd_sdio.c b/drivers/char/diag/diagfwd_sdio.c
index 8be9f46..f3873aa 100644
--- a/drivers/char/diag/diagfwd_sdio.c
+++ b/drivers/char/diag/diagfwd_sdio.c
@@ -124,10 +124,11 @@
 
 int diagfwd_disconnect_sdio(void)
 {
-	driver->in_busy_sdio = 1;
 	usb_diag_free_req(driver->mdm_ch);
-	if (driver->sdio_ch && (driver->logging_mode == USB_MODE))
+	if (driver->sdio_ch && (driver->logging_mode == USB_MODE)) {
+		driver->in_busy_sdio = 1;
 		diag_sdio_close();
+	}
 	return 0;
 }