Remove explicit vuart enable from startup_hacks.sh

Newer kernels always enable the vuart device and do not expose
the enable file for the vuart device.

Change-Id: Id8d341322f19112d102c9df8a9e6bdb7e2ef6337
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
diff --git a/hacks/startup_hacks.sh b/hacks/startup_hacks.sh
index 3a93e90..7e96ccf 100644
--- a/hacks/startup_hacks.sh
+++ b/hacks/startup_hacks.sh
@@ -6,4 +6,3 @@
 VUART=/sys/devices/platform/ahb/ahb:apb/1e787000.vuart
 echo 4 > $VUART/sirq
 echo 0x3f8 > $VUART/lpc_address
-echo 1 > $VUART/enabled