drm/i915/bios: rename intel_parse_bios to intel_bios_init

While at it, move the declaration to where everything else is declared.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/7d9d879603038889f0128cf7cbbd9f591edc11dd.1450089383.git.jani.nikula@intel.com