security/tpm: remove tis_close()

This function was never called from outside of drivers and
src/drivers/pc80/tpm/tis.c was the only one doing it in a questionable
way.

tpm_vendor_cleanup() also isn't needed as one of tis_close() functions
was its only caller.

Change-Id: I9df76adfc21fca9fa1d1af7c40635ec0684ceb0f
Ticket: https://ticket.coreboot.org/issues/433
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68989
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/drivers/crb/tis.c

@@ -53,19 +53,6 @@ int tis_open(void)
 	return 0;
 }
 
-int tis_close(void)
-{
-	if (tpm_is_open) {
-		/*
-		 * Do we need to do something here, like waiting for a
-		 * transaction to stop?
-		 */
-		tpm_is_open = 0;
-	}
-
-	return 0;
-}
-
 int tis_init(void)
 {
 	struct tpm2_info info;