[device] Modify configuration and add led_proc_init.soc on as7726-32x

[dereksun01]

Signed-off-by: derek_sun derek_sun@edge-core.com

• What I did
  Modify configuration file and add led_proc_init.soc.

• How I did it

1. Modify configuration file path in sai.profile.
2. Modify configuration file for as7726_32x.
3. Add led_proc_init.soc and custom_led.bin

• How to verify it

1. Testing on as7726_32x.
2. Broadcom shell command line:
   -) led and led status.
   -) ps and version.
3. SONiC command line: show version and show interface status.

• Description for the changelog
  Modify configuration and add led_proc_init.soc on as7726_32x.

• A picture of a cute animal (not mandatory but encouraged)

[dereksun01]

@lguohan

Could this PR be merged to 201911 branch too ? thanks.