laurel_sprout: Disable SF backpressure

Change-Id: I4d5e9ec52901a8b7da9c0c439417a4ac90c512b3
diff --git a/system.prop b/system.prop
index d4ccd29..e2eb299 100644
--- a/system.prop
+++ b/system.prop
@@ -43,6 +43,7 @@
 debug.sf.enable_hwc_vds=1
 debug.gralloc.enable_fb_ubwc=1
 debug.sf.latch_unsignaled=1
+debug.sf.disable_backpressure=1
 debug.sf.recomputecrop=0
 dev.pm.dyn_samplingrate=1