nvl32: Add BMC_INIT_DONE assertion

Asserts bmc init done in platform-init instead of u-boot

Tested: nvl32-obmc still boots after removing this from
u-boot

Change-Id: I9328d595983447697e2979583c6ba6da6821df96
Signed-off-by: Marc Olberding <molberding@nvidia.com>
diff --git a/nvidia/nvl32.cpp b/nvidia/nvl32.cpp
index b2779cc..79e396f 100644
--- a/nvidia/nvl32.cpp
+++ b/nvidia/nvl32.cpp
@@ -504,6 +504,7 @@
 int init_nvl32()
 {
     setup_devmem();
+    gpio::set("BMC_INIT_DONE", 1);
     handle_passthrough_registers(false);
     sd_notify(0, "READY=1");