Build test cases by default

A default `meson build` does not build the test cases in the repository,
having the test cases built by default is a consistent behaviour across
all the openbmc repos.So making the change to build the tests by default
unless explicitly disabled.

Change-Id: I999e87a3711bc98f644c77f79700c0d55e5fede2
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
diff --git a/meson_options.txt b/meson_options.txt
index d4b7fa6..2c99b02 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -3,7 +3,8 @@
 # command : meson configure -Dfeature_name=enabled
 
 option( 'tests', type : 'feature',
-        description: 'Build unit tests'
+         value: 'enabled',
+         description: 'Build unit tests'
       )
 
 # Commandline variables list