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/cmd/ximg.c b/cmd/ximg.c
index 65ba413..8533d0d 100644
--- a/cmd/ximg.c
+++ b/cmd/ximg.c
@@ -200,7 +200,7 @@
 
 				while (l > 0) {
 					tail = (l > CHUNKSZ) ? CHUNKSZ : l;
-					WATCHDOG_RESET();
+					schedule();
 					memmove(to, from, tail);
 					to += tail;
 					from += tail;