drivers: gpio: xlnx_ps: use DT_INST_FOREACH_CHILD_STATUS_OKAY_SEP

Simplify driver by using DT_INST_FOREACH_CHILD_STATUS_OKAY_SEP (avoids
DT_DRV_INST and auxiliary macro).

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

drivers/gpio/gpio_xlnx_ps.c

@@ -94,11 +94,10 @@ static void gpio_xlnx_ps_isr(const struct device *dev)
  * devices for the parent controller device's config data struct
  * specified in the device tree.
  */
-#define GPIO_XLNX_PS_CHILD_CONCAT(idx) DEVICE_DT_GET(idx),
 
 #define GPIO_XLNX_PS_GEN_BANK_ARRAY(idx)\
 static const struct device *const gpio_xlnx_ps##idx##_banks[] = {\
-	DT_FOREACH_CHILD_STATUS_OKAY(DT_DRV_INST(idx), GPIO_XLNX_PS_CHILD_CONCAT)\
+	DT_INST_FOREACH_CHILD_STATUS_OKAY_SEP(idx, DEVICE_DT_GET, (,))\
 };
 
 /* Device config & run-time data struct creation macros */