ARM: shmobile: use FSI driver's audio clock on armadillo800eva

Current FSI driver can control audio clock without platform
call-back functions
This patch removed board-specific call-back/settings

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms@verge.net.au>