drivers: adc: update new macro name in RTD 2.0.1

FEATURE_ADC_MAX_CHN_COUNT changed to ADC_SAR_IP_MAX_CHN_COUNT
in RTD 2.0.1

Signed-off-by: Tu Nguyen Van <tu.nguyenvan@nxp.com>

Author: tunguyen4585

drivers/adc/adc_nxp_s32_adc_sar.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 NXP
+ * Copyright 2023-2025 NXP
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -22,6 +22,10 @@ LOG_MODULE_REGISTER(adc_nxp_s32_adc_sar, CONFIG_ADC_LOG_LEVEL);
 #define ADC_NXP_S32_GROUPCHAN_2_PHYCHAN(group, channel)	\
 						(ADC_SAR_IP_HW_REG_SIZE * group + channel)
 
+#if !defined(FEATURE_ADC_MAX_CHN_COUNT)
+#define FEATURE_ADC_MAX_CHN_COUNT ADC_SAR_IP_MAX_CHN_COUNT
+#endif
+
 struct adc_nxp_s32_config {
 	ADC_Type *base;
 	uint8_t instance;