drm/i915: fix 64bit divide

ERROR: "__udivdi3" [drivers/gpu/drm/i915/i915.ko] undefined!
ERROR: "__divdi3" [drivers/gpu/drm/i915/i915.ko] undefined!

Store the frequency in kHz and drop 64bit divisions.

v2: Use div64_u64 (Matthew)

v3: store frequency in kHz to avoid 64bit divs (Chris/Ville)

Fixes: dab9178333 ("drm/i915: expose command stream timestamp frequency to userspace")
Reported-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171113233455.12085-3-lionel.g.landwerlin@intel.com
Reviewed-by: Ewelina Musial <ewelina.musial@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 42813f4..171b86f 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -420,7 +420,7 @@ static int i915_getparam(struct drm_device *dev, void *data,
 			return -ENODEV;
 		break;
 	case I915_PARAM_CS_TIMESTAMP_FREQUENCY:
-		value = INTEL_INFO(dev_priv)->cs_timestamp_frequency;
+		value = 1000 * INTEL_INFO(dev_priv)->cs_timestamp_frequency_khz;
 		break;
 	default:
 		DRM_DEBUG("Unknown parameter %d\n", param->param);