doc: Update header files names

Update header files containing i915_perf_stream, i915_perf_stream_ops
and i915_oa_ops definitions since they have been moved from i915_drv.h
to i915_perf_types.h.

Cc: Robert Bragg <robert@sixbynine.org>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Anna Karas <anna.karas@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191022100906.16597-1-anna.karas@intel.com

Documentation/gpu/i915.rst

@@ -550,9 +550,9 @@ i915 Perf Stream
 This section covers the stream-semantics-agnostic structures and functions
 for representing an i915 perf stream FD and associated file operations.
 
-.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
+.. kernel-doc:: drivers/gpu/drm/i915/i915_perf_types.h
    :functions: i915_perf_stream
-.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
+.. kernel-doc:: drivers/gpu/drm/i915/i915_perf_types.h
    :functions: i915_perf_stream_ops
 
 .. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
@@ -577,7 +577,7 @@ for representing an i915 perf stream FD and associated file operations.
 i915 Perf Observation Architecture Stream
 -----------------------------------------
 
-.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
+.. kernel-doc:: drivers/gpu/drm/i915/i915_perf_types.h
    :functions: i915_oa_ops
 
 .. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c