mariadb: drop the anonymous function and use proper install layout

The anonymous function redefined bindir to bindir_noprefix (and
others), which broke the sstate between build dirs.

The redefined *_noprefix was to used to pass to the INSTALL_*
variables to change the layout as we want, but in fact we can
do this in other ways instead of the pain one:

1) Change the default layout and a little adjustment.
There are 4 install layout: STANDALONE(default), RPM, DEB and SVR4.
And RPM is the one close to what we are using.

2) Don't use prefix and pass full paths to INSTALL_*.
The mariadb's cmake define some of the INSTALL_* relative to
CMAKE_INSTALL_PREFIX, So we can use empty CMAKE_INSTALL_PREFIX,
then we can pass our full paths to INSTALL_* directly.

This patch set the default layout to RPM and pass paths only for:
- INSTALL_DOCDIR: no prefix prepending, so ${datadir} works.
- INSTALL_LIBDIR/INSTALL_PLUGINDIR: use ${baselib}.

The mysql-test is moved from /usr to /usr/share which is more
reasonable, fix the FILES inclusion accordingly.

Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>