trusty: Switch to dmabuf for coverage shared memory

Trusty shared memory now uses dmabuf instead of memfd. Switch the
coverage buffer allocation to use libdmabufheap.

Test: atest libtrusty_coverage_test
Bug: None
Change-Id: I067dd0774d19b42380ce5cb8ceb3541fa77ef9f0
diff --git a/trusty/coverage/Android.bp b/trusty/coverage/Android.bp
index 6038d44..daa6f03 100644
--- a/trusty/coverage/Android.bp
+++ b/trusty/coverage/Android.bp
@@ -28,6 +28,7 @@
     shared_libs: [
         "libbase",
         "liblog",
+        "libdmabufheap",
     ],
 }
 
@@ -43,6 +44,7 @@
     shared_libs: [
         "libbase",
         "liblog",
+        "libdmabufheap",
     ],
     require_root: true,
 }