drm/i915: Fix indentation for intel_ddi_clk_select

drivers/gpu/drm/i915/intel_ddi.c:2098 intel_ddi_clk_select() warn: inconsistent indenting

References: 8edcda12 ("drm/i915: Protect DDI port to DPLL map from theoretical race.")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171219112649.9388-1-chris@chris-wilson.co.uk