power-utils: Initially use i2c in updater

Create I2CDevice in updater and invoke read() in doUpdate(), that could
be used in future.
Use mocked I2CInterface in updater's unit test case.

Tested: Manually verify on Witherspoon that the i2c device is opened
        and closed during PSU code update.

Signed-off-by: Lei YU <mine260309@gmail.com>
Change-Id: Ie3d9f0565a2ceb000f489647a58ca967a2ef0c38
diff --git a/tools/power-utils/test/meson.build b/tools/power-utils/test/meson.build
index 45052ad..1f23ad0 100644
--- a/tools/power-utils/test/meson.build
+++ b/tools/power-utils/test/meson.build
@@ -9,7 +9,7 @@
             phosphor_logging,
         ],
         implicit_include_directories: false,
-        include_directories: '../../..',
+        include_directories: libpower_inc,
         link_with: [
             libpower,
         ],
@@ -25,10 +25,11 @@
         '../updater.cpp',
         dependencies: [
             gtest,
+            gmock,
             phosphor_logging,
         ],
         implicit_include_directories: false,
-        include_directories: '../../..',
+        include_directories: [libpower_inc, libi2c_inc],
         link_with: [
             libpower,
         ],