package/uboot-tols: fix dependency of comment about FIT support

When commit 031130a4 added the dependency on shared libs for FIT support
in uboot-tools, the dependency of the comment was added exactly as the
dependency of the symbol.

That means the comment is shown when FIT support is possible, and hidden
when it is not, while we want it the other way around...

Fix the dependency.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>