ccache: do not use ccache if it is explicitly forbidden

ccache: do not use ccache if it is explicitly forbidden

Some recipes explicitly disable ccache via CCACHE_DISABLE variable since
they are known issues with ccache in those recipes.
This setting should not be ignored also when ccache in in HOSTOOLS.

Rework a hard to read if clause so that it is in format
if (not CCACHE_DISABLE and (cond1 or cond2 or cond2)):

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>