powerpc64/ftrace: Include ftrace.h needed for enable/disable calls
this_cpu_disable_ftrace and this_cpu_enable_ftrace are inlines in
ftrace.h Without it included, the build fails.
Fixes: a4bc64d305af ("powerpc64/ftrace: Disable ftrace during kvm entry/exit")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Luke Dashjr <luke-jr+git@utopios.org>
Acked-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Luke Dashjr