[chassisd]: Updated the API get_platform_info() to return running/detected ASIC's count (#16539)

previously, get_num_asics() returns the maximum number of asics. however, the asic_count 
should be actual number of asics populated which can be get from get_asic_presence_list().

ADO: 25158825

Signed-off-by: Abhishek Dosi <abdosi@microsoft.com>

src/sonic-py-common/sonic_py_common/device_info.py

@@ -367,7 +367,7 @@ def get_platform_info(config_db=None):
     if hw_info_dict:
         return hw_info_dict
 
-    from .multi_asic import get_num_asics
+    from .multi_asic import get_asic_presence_list
 
     version_info = get_sonic_version_info()
 
@@ -375,7 +375,10 @@ def get_platform_info(config_db=None):
     hw_info_dict['hwsku'] = get_hwsku()
     if version_info:
         hw_info_dict['asic_type'] = version_info.get('asic_type')
-    hw_info_dict['asic_count'] = get_num_asics()
+    try:
+        hw_info_dict['asic_count'] = len(get_asic_presence_list())
+    except:
+        hw_info_dict['asic_count'] = 'N/A'
 
     try:
         # TODO: enforce caller to provide config_db explicitly and remove its default value

src/sonic-py-common/sonic_py_common/multi_asic.py

@@ -484,4 +484,7 @@ def get_asic_presence_list():
                 for asic in asics_presence_list:
                     # asic is asid id: asic0, asic1.... asicN. Get the numeric value.
                     asics_list.append(int(get_asic_id_from_name(asic)))
+    else:
+        # This is not multi-asic, all asics should be present.
+        asics_list = list(range(0, get_num_asics()))
     return asics_list