kirkwood: lsxl: Sync defconfigs

With the recent changes in the Orion timer driver Kconfig setup, the
board specific enabling is not needed any more. This patch sync's these
2 boards with their current defconfig version.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Michael Walle <michael@walle.cc>
Tested-by: Tony Dinh <mibodhi@gmail.com>