timer: Change timer util functions to 64-bit

Since mono_time is now 64-bit, the utility functions interfacing with
mono_time should also be 64-bit so precision isn't lost.

Fixed build errors related to printing the now int64_t result of
stopwatch_duration_[m|u]secs in various places.

BUG=b:237082996
BRANCH=All
TEST=Boot dewatt

Change-Id: I169588f5e14285557f2d03270f58f4c07c0154d5
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66170
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

src/soc/intel/elkhartlake/tsn_gbe.c

@@ -39,7 +39,7 @@ enum cb_err phy_gmii_ready(void *base)
 
 	} while (!stopwatch_expired(&sw));
 
-	printk(BIOS_ERR, "%s Timeout after %ld msec\n", __func__,
+	printk(BIOS_ERR, "%s Timeout after %lld msec\n", __func__,
 			stopwatch_duration_msecs(&sw));
 	return CB_ERR;
 }