Support for static and dynamic attrs as part of stormond implementation (#439)

* Added support for INNODISK SMART attributes

* Fixed a bug with get_reserved_blocks() function

* Added support for Micron and Intel vendors. Fixed a bug with generic temperature parsing.

* Renamed ssd_base -> storage_base, added class for common calls, modified child class implementation accordingly

* Fixed a looping bug

* renamed sonic_ssd --> sonic_storage, removed 'ssd_' prefix from child classes

* Cleaned up impl per core algorithm changes, defined in HLD

* Renamed SSD and EMMC UTs per naming convention

* Made following changes based on prgeor review coments:

storage_devices.py:
	Moved imports to the beginning of file
	renamed function to _storage_device_object_factory
	Above function now returns an object

storage_common.py:
	Changed logic to only get reads and writes using psutil library.

* Added UTs, fixed bugs in ssd.py surfaced by UTs

* Added more UTs, fixed issue surafced by said UTs

* Increased coverage, cleaned up SsdUtil

* Added more UT coverage

* Addressed review comments, changed UT accordingly

* Increased UT coverage

* Removed the underscore per naming convention

* Fixed the following in ssd.py:

	Changed parse_id_number logic to prevent phantom regex matches
	Fixed a bug in parse_id_number that was causing the code to disregard vendor_ssd_info
	Fixed issues with Innodisk and Virtium parsers
        Fixed a ValueError bug in Virtium parser logic

Added UTs to test the various changes

* Fixed potential issue with parse_id_number not reconciling leading/trailing spaces

* Changed comment to better reflect class intent

* Fixed a bug where stormond was calling a function not defined for EmmcUtil objects

* Fixed fetch_parse_info error on emmc devices

* Added safeguards against vendor utilities failing

* switched from logger to syslogger per review

* Moved log to within class.

Author: ashwnsri

setup.py

@@ -37,7 +37,7 @@
         'sonic_platform_base',
         'sonic_platform_base.sonic_eeprom',
         'sonic_platform_base.sonic_sfp',
-        'sonic_platform_base.sonic_ssd',
+        'sonic_platform_base.sonic_storage',
         'sonic_platform_base.sonic_pcie',
         'sonic_platform_base.sonic_thermal_control',
         'sonic_platform_base.sonic_xcvr',

sonic_platform_base/sonic_ssd/ssd_generic.py

@@ -1,21 +1,22 @@
 #
-# ssd_emmc.py
+# emmc.py
 #
 # Implementation of SSD Utility API for eMMC.
 # It reads eMMC health, model, firmware, and serial from /sys/block/*.
 #
 
 try:
     import os
-    from .ssd_base import SsdBase
+    from .storage_common import StorageCommon
 except ImportError as e:
     raise ImportError(str(e) + "- required module not found")
 
 
-class EmmcUtil(SsdBase):
+class EmmcUtil(StorageCommon):
     def __init__(self, diskdev):
         self.diskdev = diskdev
         self.path = os.path.join('/sys/block', os.path.basename(diskdev))
+        StorageCommon.__init__(self, diskdev)
 
     def _read_device_entry(self, entry, default=None):
         path = os.path.join(self.path, 'device', entry)
@@ -49,3 +50,15 @@ def get_serial(self):
 
     def get_vendor_output(self):
         return ''
+
+    def get_disk_io_reads(self):
+        return 'N/A'
+
+    def get_disk_io_writes(self):
+        return 'N/A'
+
+    def get_reserved_blocks(self):
+        return 'N/A'
+
+    def fetch_parse_info(self, diskdev=None):
+        return