[SWDEV-489696] Improve AMD SMI Python APIs Functional and Unit Testing (#468)

* Adding python unit tests
* Remove duplicate functions definitions
* Added missing classes for __init__ for py-interface

---------

Signed-off-by: josnarlo <Joseph.Narlo@amd.com>
Signed-off-by: Maisam Arif <Maisam.Arif@amd.com>

py-interface/__init__.py

@@ -259,6 +259,9 @@ from .amdsmi_interface import AmdSmiDeviceType
 from .amdsmi_interface import AmdSmiMmIp
 from .amdsmi_interface import AmdSmiFwBlock
 from .amdsmi_interface import AmdSmiClkType
+from .amdsmi_interface import AmdSmiClkLimitType
+
+from .amdsmi_interface import AmdSmiRegType
 from .amdsmi_interface import AmdSmiTemperatureType
 from .amdsmi_interface import AmdSmiDevPerfLevel
 from .amdsmi_interface import AmdSmiEventGroup

py-interface/amdsmi_interface.py

@@ -207,6 +207,9 @@ class AmdSmiClkType(IntEnum):
     DCLK0 = amdsmi_wrapper.AMDSMI_CLK_TYPE_DCLK0
     DCLK1 = amdsmi_wrapper.AMDSMI_CLK_TYPE_DCLK1
 
+class AmdSmiClkLimitType(IntEnum):
+    MIN = amdsmi_wrapper.CLK_LIMIT_MIN
+    MAX = amdsmi_wrapper.CLK_LIMIT_MAX
 
 class AmdSmiTemperatureType(IntEnum):
     EDGE = amdsmi_wrapper.AMDSMI_TEMPERATURE_TYPE_EDGE

src/amd_smi/amd_smi.cc

@@ -3303,7 +3303,9 @@ amdsmi_status_t amdsmi_get_gpu_reg_table_info(
 }
 
 void amdsmi_free_name_value_pairs(void *p) {
-    free(p);
+    if (p)
+        free(p);
+    return;
 }
 
 amdsmi_status_t