subkey: regenerate the subkey signatures

We have increased the size of the default key in optee_os, necessitating
re-signing the keys used in the subkey tests (xtest 1039). The existing
keys have been updated using these commands:

$ cd optee_test/ta

$ ../../optee_os/scripts/sign_encrypt.py sign-subkey \
    --uuid f04fa996-148a-453c-b037-1dcfbad120a6 \
    --key ../../optee_os/keys/default_ta.pem \
    --in top_level_subkey.pem \
    --out top_level_subkey.bin \
    --max-depth 4 --name-size 64 --subkey-version 1

$ ../../optee_os/scripts/sign_encrypt.py sign-subkey \
    --uuid 1a5948c5-1aa0-518c-86f4-be6f6a057b16 \
    --key top_level_subkey.pem \
    --subkey top_level_subkey.bin \
    --in mid_level_subkey.pem \
    --out mid_level_subkey.bin \
    --name-size 64 --subkey-version 1 --name mid_level_subkey

$ ../../optee_os/scripts/sign_encrypt.py sign-subkey \
    --uuid a720ccbb-51da-417d-b82e-e5445d474a7a \
    --key ../../optee_os/keys/default_ta.pem \
    --in identity_subkey2.pem \
    --out identity_subkey2.bin \
    --max-depth 0 --name-size 0 --subkey-version 1

 It is important to note that these are test keys intended solely for
 testing purposes.

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

Author: jockebech