libxkbcommon: replace locale dependecy from RDEPENDS to RRECOMMENDS

libxkbcommon: replace locale dependecy from RDEPENDS to RRECOMMENDS

The error described does not occur in all cases where libxkbcommon is
used. As example, a Qt application that depends on libxkbcommon might
not require any locales to be installed.

Add it to RRECOMMENDS, as libxkbcommon does not seen to have any hard
dependency on libx11-compose-data or libx11-locale. This change can help
users decide to disable it and save some space on the rootfs.

Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>