timer-uclass: add timer_get_ops() macro

Align timer uclass with the other subsystems and provide a timer_get_ops()
convenience macro.

Using this instead of the generic device_get_ops() also prevents
-Wdiscarded-qualifiers warnings when used with non-const variables.

Signed-off-by: Ovidiu Panait <ovpanait@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20221012053656.1492457-1-ovpanait@gmail.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

include/timer.h

@@ -6,6 +6,8 @@
 #ifndef _TIMER_H_
 #define _TIMER_H_
 
+#define timer_get_ops(dev)	((struct timer_ops *)(dev)->driver->ops)
+
 /**
  * dm_timer_init() - initialize a timer for time keeping. On success
  * initializes gd->timer so that lib/timer can use it for future