host-cmake: Install with install/fast target

Use install/fast target in order to skip compilation in installation
step. The same trick has just been used in pkg-cmake.mk for all CMake
packages.

Signed-off-by: Cédric Marie <cedric.marie@openmailbox.org>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Tested-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>