spi: hspi: fixup long delay time

Current HSPI driver is using msleep(20) on hspi_status_check_timeout(),
but it was too long delay for SPI device.
Bock-W board SPI access was too slow without this patch.
This patch uses udelay(10) for it.

Tested-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>