libssh2: remove util-linux-col from ptest dependencies

libssh2: remove util-linux-col from ptest dependencies

After util-linux upgrade to 2.40.1, we got the following QA issue
on musl:

  WARNING: libssh2-1.11.0-r0 do_package_qa: QA Issue: libssh2-ptest
  rdepends on util-linux-col, but it isn't a build dependency? [build-deps]

The issue appeared because new version util-linux has disabled
building out col on musl[1]. In short, the reason is that col in
util-linux requires something that musl does not provide.

This 'util-linux-col' dependency was added in 2021, at that time
the libssh2's version is 1.9.0. Now the version is 1.11.0 and I tested
its ptest, it does not require util-linux-col to succeed.

[1] https://github.com/util-linux/util-linux/commit/8886d84e25a457702b45194d69a47313f76dc6bc

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>