src/vboot: mark factory_initialze_tpm() as static

This function is not used anywhere else in the code.

BRANCH=none
BUG=none
TEST=reef and kevin boards (using tpm1.2 and tpm2.0 respectively)
     build successfully.

Change-Id: Ifcc345ae9c22b25fdcfc2e547e70766021d27e32
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://review.coreboot.org/17387
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins)

src/vboot/secdata_tpm.c

@@ -329,7 +329,14 @@ uint32_t antirollback_lock_space_rec_hash(void)
 }
 #endif
 
-uint32_t factory_initialize_tpm(struct vb2_context *ctx)
+/**
+ * Perform one-time initializations.
+ *
+ * Create the NVRAM spaces, and set their initial values as needed.  Sets the
+ * nvLocked bit and ensures the physical presence command is enabled and
+ * locked.
+ */
+static uint32_t factory_initialize_tpm(struct vb2_context *ctx)
 {
 	uint32_t result;