Add sysfs mount for pmon container (sonic-net#24017)

Why I did it
For platform using sysfs, the current pmon is broken.

admin@sonic:~$ docker exec -it pmon bash
root@sonic:/# python3
Python 3.11.2 (main, Apr 28 2025, 14:11:48) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> open('/sys/class/i2c-adapter/i2c-71/71-0050/eeprom', mode='r+b', buffering=0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: [Errno 30] Read-only file system: '/sys/class/i2c-adapter/i2c-71/71-0050/eeprom'
After this fix

admin@sonic:~$ docker exec -it pmon bash
root@sonic:/# python3
Python 3.11.2 (main, Apr 28 2025, 14:11:48) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> open('/sys/class/i2c-adapter/i2c-71/71-0050/eeprom', mode='r+b', buffering=0)
<_io.FileIO name='/sys/class/i2c-adapter/i2c-71/71-0050/eeprom' mode='rb+' closefd=True>

This regression was introduced by sonic-net#23457

Author: qiluo-msft

rules/docker-platform-monitor.mk

@@ -57,6 +57,8 @@ $(DOCKER_PLATFORM_MONITOR)_RUN_OPT += -v /host/reboot-cause:/host/reboot-cause:r
 $(DOCKER_PLATFORM_MONITOR)_RUN_OPT += -v /host/pmon/stormond:/usr/share/stormond:rw
 $(DOCKER_PLATFORM_MONITOR)_RUN_OPT += -v /var/run/platform_cache:/var/run/platform_cache:ro
 $(DOCKER_PLATFORM_MONITOR)_RUN_OPT += -v /usr/share/sonic/device/pddf:/usr/share/sonic/device/pddf:ro
+# Add sysfs mounts for hardware access
+$(DOCKER_PLATFORM_MONITOR)_RUN_OPT += -v /sys/:/sys/:rw
 
 # Mount Arista python library on Aboot images to be used by plugins
 $(DOCKER_PLATFORM_MONITOR)_aboot_RUN_OPT += -v /usr/lib/libsfp-eeprom.so:/usr/lib/libsfp-eeprom.so:ro