cyclic: Use schedule() instead of WATCHDOG_RESET()

Globally replace all occurances of WATCHDOG_RESET() with schedule(),
which handles the HW_WATCHDOG functionality and the cyclic
infrastructure.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Tom Rini <trini@konsulko.com> [am335x_evm, mx6cuboxi, rpi_3,dra7xx_evm, pine64_plus, am65x_evm, j721e_evm]
diff --git a/drivers/serial/serial_mpc8xx.c b/drivers/serial/serial_mpc8xx.c
index 0978930..aeae6ae 100644
--- a/drivers/serial/serial_mpc8xx.c
+++ b/drivers/serial/serial_mpc8xx.c
@@ -187,7 +187,7 @@
 	setbits_be16(&rtx->txbd.cbd_sc, BD_SC_READY);
 
 	while (in_be16(&rtx->txbd.cbd_sc) & BD_SC_READY)
-		WATCHDOG_RESET();
+		schedule();
 
 	return 0;
 }
@@ -204,7 +204,7 @@
 
 	/* Wait for character to show up. */
 	while (in_be16(&rtx->rxbd.cbd_sc) & BD_SC_EMPTY)
-		WATCHDOG_RESET();
+		schedule();
 
 	/* the characters are read one by one,
 	 * use the rxindex to know the next char to deliver