vboot: update VbExNvStorageWrite function

Going forwards, vb2ex_commit_data will be used to flush both
nvdata and secdata.

The patch that is circularly dependent on this lies between a patch that
makes vboot no longer build and the patch that fixes that, so we have to
pull the whole thing in at once to sort out the mess.

Updating from commit id 1c4dbaa0:
2019-11-18 Julius Werner   Makefile: Fix typo for MOCK_TPM

to commit id 695c56dc:
2019-12-04 Julius Werner   Makefile: Make loop unrolling fully
                           controllable by the caller

BUG=b:124141368, chromium:1006689
TEST=make clean && make test-abuild
BRANCH=none

Change-Id: Ia2612da0df101cd3c46151dbce728633a39fada1
Signed-off-by: Joel Kitching <kitching@google.com>
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37315
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/security/vboot/ec_sync.c b/src/security/vboot/ec_sync.c
index c2a6b25..8a3ba71 100644
--- a/src/security/vboot/ec_sync.c
+++ b/src/security/vboot/ec_sync.c
@@ -399,9 +399,9 @@
 /*
  * Write opaque data into NV storage region.
  */
-vb2_error_t VbExNvStorageWrite(const uint8_t *buf)
+vb2_error_t vb2ex_commit_data(struct vb2_context *ctx)
 {
-	save_vbnv(buf);
+	save_vbnv(ctx->nvdata);
 	return VB2_SUCCESS;
 }