plat: marvell: Update SUBVERSION to match Marvell's forked version

Marvell's TF-A fork has SUBVERSION set to devel-18.12.2.

The only differences between Marvell's devel-18.12.0 and devel-18.12.2
versions are documentation updates and cherry-picked patches from TF-A
upstream repository.

So upstream TF-A has already all changes from Marvell's TF-A devel-18.12.2
fork and therefore update SUBVERSION to reflect this state.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I5ce946a5176a5cbf124acd8037392463d586b072
diff --git a/plat/marvell/version.mk b/plat/marvell/version.mk
index e072e12..bb22255 100644
--- a/plat/marvell/version.mk
+++ b/plat/marvell/version.mk
@@ -1 +1 @@
-SUBVERSION = devel-18.12.0
+SUBVERSION = devel-18.12.2