build-unit-test-docker: add libpciaccess-dev

This library will be used by phosphor-ipmi-flash.

Signed-off-by: Benjamin Fair <benjaminfair@google.com>
Change-Id: I082838acfed66a6539cc3a337644116cdf509eed
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index 6b658a3..31bca06 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -259,7 +259,8 @@
     protobuf-compiler \
     libgpiod-dev \
     device-tree-compiler \
-    cppcheck
+    cppcheck \
+    libpciaccess-dev
 
 RUN update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-10 1000 \
   --slave /usr/bin/g++ g++ /usr/bin/g++-10 \