drm/edid: Swap some operands in for_each_displayid_db()

A+B on the previous line, B+A on the next line. Brain hurts.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313162054.16009-3-ville.syrjala@linux.intel.comReviewed-by: Alex Deucher <alexander.deucher@amd.com>

include/drm/drm_displayid.h

@@ -97,7 +97,7 @@ struct displayid_detailed_timing_block {
 	     (idx) + sizeof(struct displayid_block) <= (length) && \
 	     (idx) + sizeof(struct displayid_block) + (block)->num_bytes <= (length) && \
 	     (block)->num_bytes > 0; \
-	     (idx) += (block)->num_bytes + sizeof(struct displayid_block), \
+	     (idx) += sizeof(struct displayid_block) + (block)->num_bytes, \
 	     (block) = (struct displayid_block *)&(displayid)[idx])
 
 #endif