src/poky:openssl: do not tweak so names, use PRIVATE_LIBS instead

The tweaking was not sufficient to prevent package dependency issues,
but there is a standard mechanism to do exactly that kind of prevention
which I wasn't aware of.

(From OE-Core rev: 1e75fead42f27723e720686f5a5233dc5acbe5b3)

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>