crypto: ccree - Remove debugfs when platform_driver_register failed

When platform_driver_register failed, we need to remove debugfs,
which will caused a resource leak, fix it.

Failed logs as follows:
[   32.606488] debugfs: Directory 'ccree' with parent '/' already present!

Fixes: 4c3f9727 ("crypto: ccree - introduce CryptoCell driver")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>