USP-based SPI need a disable and enable, otherwise it doesn't work.
this patch adds it as HW initialization.
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NMark Brown <broonie@kernel.org>