drm/i915: Rename global i915 to i915_modparams

drm/i915: Rename global i915 to i915_modparams

Our global struct with params is named exactly the same way
as new preferred name for the drm_i915_private function parameter.
To avoid such name reuse lets use different name for the global.

v5: pure rename
v6: fix

Credits-to: Coccinelle
@@
identifier n;
@@
(
-	i915.n
+	i915_modparams.n
)

Signed-off-by: Michal Wajdeczko <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Ville Syrjala <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Acked-by: Joonas Lahtinen <[email protected]>
Signed-off-by: Jani Nikula <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]