Add pkgconfig files

[tiennou]

This adds support for automatically generating pkgconfig files for the mbedcrypto library.

Exctracted from Mbed-TLS/mbedtls#1753.

[Patater]

This currently breaks the test_cmake_as_subdirectory test in all.sh. Could you please fix?

Thanks!

[Patater]

Needs work to pass ./tests/scripts/all.sh testing.

[piotr-now]

Needs work to pass ./tests/scripts/all.sh testing.

./tests/scripts/all.sh requires a lot of binaries which have to be installed manually. You can also run this tests by running ./tests/scripts/all-in-docker.sh. All required packages should be installed automatically in case of second script

[tiennou]

all/scripts/all-in-docker.ssh reported the following :

[snip]
 ---> a8ddfff48cff
Step 26/26 : RUN pip3 install --no-cache-dir     mbed-host-tests     mock
 ---> Using cache
 ---> 6b81a40296b7
Successfully built 6b81a40296b7
Successfully tagged armmbed/mbedtls-test:bionic
fatal: not a git repository: /Users/tiennou/Projects/mbedtls/crypto/../.git/modules/crypto
Warning - the configuration file 'include/mbedtls/config.h' has been edited. 
You can either delete or preserve your work, or force the test by rerunning the
script as: tests/scripts/all.sh --force

Not sure how to proceed, I've asked for --force but now it's making my CPU run hot 😉. My working copy is clean, it just predates the mbedcrypto split, so maybe something went wrong with the submodule ? I haven't seen git report any issue with it though…

EDIT: The following works : git --git-dir=/Users/tiennou/Projects/mbedtls/crypto/../.git/modules/crypto ls-files and reports the list of files in HEAD, so the repo is fine.

EDIT EDIT: I've made a real clone of my submodule, and it works 🤷‍♂.

[gilles-peskine-arm]

Mbed Crypto has been merged back into Mbed TLS. Due to the nature of this pull request, it does not make sense to apply it to Mbed Crypto separately. Please make further updates on the corresponding Mbed TLS pull request: Mbed-TLS/mbedtls#1753