drm/i915/glk: Convert a few more IS_BROXTON() to IS_GEN9_LP()

Commit cc3f90f0 ("drm/i915/glk: Reuse broxton code for geminilake")
missed a few of occurences of IS_BROXTON() that should have been
coverted to IS_GEN9_LP().

v2: Cite the right commit. (Ander)

Fixes: cc3f90f0 ("drm/i915/glk: Reuse broxton code for geminilake")
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Tomasz Lis <tomasz.lis@intel.com> (v1)
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483973495-15138-1-git-send-email-ander.conselvan.de.oliveira@intel.com