The SRC_URI is updated for the base recipe, but the copy of the SRC_URI
in the override section doesn't account for this, leading to a build break:
```
| -- wechat_qrcode: Download: detect.caffemodel
| CMake Error at /opt/work/upstream/fsl-xwayland/tmp/work/cortexa53-crypto-mx8mp-fsl-linux/opencv/4.5.2.imx-r0/git/cmake/OpenCVDownload.cmake:161 (message):
| Not going to download detect.caffemodel
```
Additionally, the SRC_URI is long and complex, and copying it in our
override section does make problems like this more likely.
Fix the problem and simplify maintenance by replacing the SRC_URI copy
with a targetted override. The override section now shows only the
changes to SRC_URI.
The fix includes these related changes:
- a new patch file is added in the base recipe and is now copied locally
- the override for SRCREV_contrib is redundant and is dropped
Signed-off-by: Tom Hochstein <tom.hochstein@nxp.com>
