ANDROID: dm: android-verity: Allow android-verity to be compiled as an independent module

Exports the device mapper callbacks of linear and dm-verity-target
methods.

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I0358be0615c431dce3cc78575aaac4ccfe3aacd7
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index fa5941fc..f26ce41 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -59,6 +59,7 @@
 obj-$(CONFIG_DM_CACHE_CLEANER)	+= dm-cache-cleaner.o
 obj-$(CONFIG_DM_ERA)		+= dm-era.o
 obj-$(CONFIG_DM_LOG_WRITES)	+= dm-log-writes.o
+obj-$(CONFIG_DM_ANDROID_VERITY) += dm-android-verity.o
 
 ifeq ($(CONFIG_DM_UEVENT),y)
 dm-mod-objs			+= dm-uevent.o
@@ -67,7 +68,3 @@
 ifeq ($(CONFIG_DM_VERITY_FEC),y)
 dm-verity-objs			+= dm-verity-fec.o
 endif
-
-ifeq ($(CONFIG_DM_ANDROID_VERITY),y)
-dm-verity-objs			+= dm-android-verity.o
-endif