Build fails due to omx_ti folders not found

```
What steps will reproduce the problem?
1. Make a new, clear directory
2. Follow instructions at http://code.google.com/p/rowboat/wiki/DSP
3. Install also the DVSDK packages according to instructions.
4. Build according to instructions

What is the expected output? What do you see instead?

Build fails on IGEPv2 board because there is no omx_ti folder under
external/ti-dsp/.

What version of the product are you using? On what operating system?

Clean folder, repo init + sync latest on 2010-10-16 with:
* codec_engine_2_25_05_16.tar.gz
* dvsdk_setuplinux_3_01_00_10.bin
* cs1omap3530_setupLinux_1_01_00-prebuilt-dvsdk3.01.00.10.bin
* ti_cgt_c6000_6.1.12_setup_linux_x86.bin
* codec_engine_2_25_05_16.tar.gz
per instructions.

Operating system is not the issue.

Please provide any additional information below.

The OMX audio and video codecs, interface and overlay code does not exist when
the source and packages are fetched according to instructions. The omx_ti does
not come from any of the listed TI packages, and there is no instruction where
to get that.

I guess something is missing in the instructions or some package has changed to
not include omx_ti, or there's problems with my reading comprehension :)
```

Original issue reported on code.google.com by `jani.j.n...@gmail.com` on 17 Oct 2010 at 10:12

Start with the DSP setup instructions and inspect external/ti-dsp/ after installing the listed DVSDK and TI packages. Determine which package or instruction should provide the missing omx_ti directory, then verify that a clean IGEPv2 build completes with the required OMX audio, video, interface, and overlay sources present.

Written by the indexing model from the issue text.