CryptoPkg/OpensslLib: remove clone commands
https://bugzilla.tianocore.org/show_bug.cgi?id=1910
edk2/Readme.md has added a section to explain the correct clone
commands for submodules. Detailed steps in the OpenSSL-HOWTO.txt
are removed to avoid any inconsistency.
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>