test: config: Add a test for config_parse_logsize.

Add a unit test that validates config_parse_logsize returns
expected values.

Tested: 'make check' passed when ran under x86_64 environment.

Change-Id: I54d9478157fab3db7c2c5879d12e719e738a1099
Signed-off-by: Kun Yi <kunyi731@gmail.com>
diff --git a/configure.ac b/configure.ac
index a306b31..e705ba1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -30,7 +30,7 @@
 )
 AC_ARG_VAR(OECORE_TARGET_SYSROOT,
     [Path to the OE SDK SYSROOT])
-AS_IF([test "x$enable_oe-sdk" == "xyes"],
+AS_IF([test "x$enable_oe_sdk" == "xyes"],
     AS_IF([test "x$OECORE_TARGET_SYSROOT" == "x"],
           AC_MSG_ERROR([OECORE_TARGET_SYSROOT must be set with --enable-oe-sdk])
     )