[nrf fromlist] drivers: pwm: nrfx: add pin retention

Add pin retenion if GPD is enabled for nRF54H20.

Upstream PR #: 80672

Signed-off-by: Michał Stasiak <michal.stasiak@nordicsemi.no>
(cherry picked from commit b524b0e)

drivers/pwm/pwm_nrfx.c

@@ -13,6 +13,9 @@
 #include <zephyr/linker/devicetree_regions.h>
 #include <zephyr/cache.h>
 #include <zephyr/mem_mgmt/mem_attr.h>
+#ifdef CONFIG_SOC_NRF54H20_GPD
+#include <nrf/gpd.h>
+#endif
 
 #include <zephyr/logging/log.h>
 
@@ -274,6 +277,10 @@ static void pwm_resume(const struct device *dev)
 
 	(void)pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
 
+#ifdef CONFIG_SOC_NRF54H20_GPD
+	nrf_gpd_retain_pins_set(config->pcfg, false);
+#endif
+
 	for (size_t i = 0; i < NRF_PWM_CHANNEL_COUNT; i++) {
 		uint32_t psel;
 
@@ -302,6 +309,10 @@ static void pwm_suspend(const struct device *dev)
 	while (!nrfx_pwm_stopped_check(&config->pwm)) {
 	}
 
+#ifdef CONFIG_SOC_NRF54H20_GPD
+	nrf_gpd_retain_pins_set(config->pcfg, true);
+#endif
+
 	memset(dev->data, 0, sizeof(struct pwm_nrfx_data));
 	(void)pinctrl_apply_state(config->pcfg, PINCTRL_STATE_SLEEP);
 }