package/racehound: fix comment

package/racehound: fix comment

racehound requires a kernel >= 3.14 to be built and to run.

However, the current conditions on the corresponding comments are wrong:
  - the comment about the kernel has a dependency on the requested
    headers
  - the comment on the toolchain features does not have this condition.

Thus, the comments are not shown/hidden under the appropriate
conditions, like in this situation:
  - toolchain with headers < 3.14 (e.g. Sourcery CodeBench x86/x86_64
    2012.09 with headers 3.5)
  - kernel 4.5 enabled

this comment is shown:
    racehound needs an Linux kernel >= 3.14 to be built

So, this is incorrect, because:
 1- a kernel >= 3.14 is indeed to be built
 2- the headers version mismatch is not reported

Fix that by moving the dependency on the kernel headers to the
appropriate comment and enhance it.

Since there is no way we can know the kernel version to be built, we can
not add such a condition; still, we leave the kernel message as-is.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>