drm/i915/hdcp: Rename HCDP 1.4 enablement function

Rename hdcp 1.4 enablement function from _intel_hdcp_enable to
intel_hdcp1_enable to better represent what version of hdcp is
being enabled

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231026121139.987437-2-suraj.kandpal@intel.com