[pdk pde] Make initpde failed

[tim-rj]

Description

Steps to reproduce the issue:

1. make initpde

Describe the results you received:

make: *** No rule to make target 'initpde'.  Stop.
make[1]: *** [Makefile.work:233: initpde] Error 2
make[1]: Leaving directory '/home/sdk/ssp/sonic-buildimage'
make: *** [Makefile:8: initpde] Error 2

Describe the results you expected:
can integrate pde module into sonic.

Additional information you deem important (e.g. issue happens only occasionally):

**Output of `show version`:**

```
(paste your output here)
```

**Attach debug file `sudo generate_dump`:**

```
(paste your output here)
```

[anshuv-mfst]

Please add link to the PR.

[tim-rj]

sonic-net/SONiC#407

[ben-gale]

The code for this feature is not yet merged - see #3778 - this is why you are seeing what you are seeing.