leds: rgb: leds-qcom-lpg: Add PPG check for setting/clearing PBS triggers

Currently, all LED LPG devices will call lpg_{set,clear}_pbs_trigger()
when setting brightness regardless of if they support PPG and have PBS
triggers. Check if device supports PPG before setting/clearing PBS
triggers.

Fixes: 6ab1f766a80a ("leds: rgb: leds-qcom-lpg: Add support for PPG through single SDAM")
Fixes: 5e9ff626861a ("leds: rgb: leds-qcom-lpg: Include support for PPG with dedicated LUT SDAM")
Signed-off-by: Anjelique Melendez <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/leds/rgb/leds-qcom-lpg.c

···
 /*
  * Copyright (c) 2017-2022 Linaro Ltd
  * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
- * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 #include <linux/bits.h>
 #include <linux/bitfield.h>
···
 	u8 val = 0;
 	int rc;
 
+	if (!lpg->lpg_chan_sdam)
+		return 0;
+
 	lpg->pbs_en_bitmap &= (~lut_mask);
 	if (!lpg->pbs_en_bitmap) {
 		rc = nvmem_device_write(lpg->lpg_chan_sdam, SDAM_REG_PBS_SEQ_EN, 1, &val);
···
 {
 	u8 val = PBS_SW_TRIG_BIT;
 	int rc;
+
+	if (!lpg->lpg_chan_sdam)
+		return 0;
 
 	if (!lpg->pbs_en_bitmap) {
 		rc = nvmem_device_write(lpg->lpg_chan_sdam, SDAM_REG_PBS_SEQ_EN, 1, &val);