list cblas as dependency library

it seems dependencies are needed to be listed as part of HMAT_LIBRARIES
else we get undefined references, eg cblas:
https://build.opensuse.org/package/live_build_log/science:openturns/openturns/ScientificLinux_7/x86_64
maybe it should be the same for other libraries

is this comment related ?
```
# LINK_PRIVATE and LINK_PUBLIC keywords were introduced in 2.8.7
if(BUILD_SHARED_LIBS AND CMAKE_VERSION VERSION_GREATER 2.8.6)
    # Programs using hmat do not need to link directly with second level dependencies so we strip them all
    set(_LINK_PRIVATE LINK_PRIVATE)
    set(_LINK_PUBLIC LINK_PUBLIC)
endif()
```