serial: pl011: Initialise the hrtimers for RS485 on pl011_axi

pl011_axi_probe was missing the equivlent hrtimer initialisation
from commit 2c1fd53 ("serial: amba-pl011: Fix RTS handling in RS485 mode")
and commit 8cb4418 ("serial: amba-pl011: Switch to use hrtimer_setup()")
resulting in the kernel blowing up as soon as pl011_rs485_stop_tx
tried to use them.

Add the hrtimer initialisation.

Fixes: 120c89e ("serial: pl011: rp1 uart support")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

Author: 6by9

drivers/tty/serial/amba-pl011.c

@@ -3098,6 +3098,11 @@ static int pl011_axi_probe(struct platform_device *pdev)
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
+	hrtimer_setup(&uap->trigger_start_tx, pl011_trigger_start_tx, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL);
+	hrtimer_setup(&uap->trigger_stop_tx, pl011_trigger_stop_tx, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL);
+
 	ret = pl011_setup_port(&pdev->dev, uap, r, portnr);
 	if (ret)
 		return ret;