kvm_debug() uses pr_debug() which is already compiled out in the absence
of a DEBUG define, so remove the unnecessary ifdef DEBUG lines around
kvm_debug() calls which are littered around arch/mips/kvm/.

As well as generally cleaning up, this prevents future bit-rot due to
DEBUG not being commonly used.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>