Slight documentation tweak

Specify that DICE-based RKP implementations may also allow a ROM
extension to manage the UDS public key.

Test: The words are semantically parseable
Change-Id: I8f9c6efb01fc76318220cf1bc4a0eb3a3ad42f87
diff --git a/security/rkp/README.md b/security/rkp/README.md
index f8e1d5e..8cd1582 100644
--- a/security/rkp/README.md
+++ b/security/rkp/README.md
@@ -52,7 +52,7 @@
 * Degenerate DICE (Phase 1): A TEE root of trust key pair is used to sign
   certificate requests; a single self-signed certificate signifies this phase.
 * DICE (Phase 2): A hardware root of trust key pair is only accessible to ROM
-  code; the boot process follows the [Android Profile for
+  or ROM extension code; the boot process follows the [Android Profile for
   DICE](#android-profile-for-dice).
 * SoC vendor certified DICE (Phase 3): This is identical to Phase 2, except the
   SoC vendor also does the UDS\_pub extraction or certification in their