clocksource/drivers/timer-ti-dm: Fix finding alwon timer

Clean-up commit b6999fa1c847 ("clocksource/drivers/timer-ti-dm: Use
of_address_to_resource()") caused a regression where pa is never set
making all related SoCs fail to boot. Let's fix this by setting pa
if found.

Fixes: b6999fa1c847 ("clocksource/drivers/timer-ti-dm: Use of_address_to_resource()")
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230412064142.12726-1-tony@atomide.com

drivers/clocksource/timer-ti-dm-systimer.c

@@ -261,8 +261,10 @@ static void __init dmtimer_systimer_assign_alwon(void)
 		if (of_address_to_resource(np, 0, &res))
 			continue;
 
+		pa = res.start;
+
 		/* Quirky omap3 boards must use dmtimer12 */
-		if (quirk_unreliable_oscillator && res.start == 0x48318000)
+		if (quirk_unreliable_oscillator && pa == 0x48318000)
 			continue;
 
 		of_node_put(np);