oprofile: set correct kernel path

oprofile's "configure" was always looking at the configuration of the host
kernel, not the target kernel. This patch instructs oprofile to use the
target kernel to configure itself.

Signed-off-by: Bogdan Marinescu <bogdan.a.marinescu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>