drm/i915/hdcp: Clean up local variables

Eliminate the inconsistencies in the hdcp code local variables:
- use dev_priv over dev
- use to_i915() instead of dev->dev_private
- initialize variables when declaring them
- a bit of declaration suffling to appease ocd

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191204180549.1267-10-ville.syrjala@linux.intel.com


Reviewed-by: Ramalingam C <ramalingam.c@intel.com>