ALSA: ASoC: Fix some minor errors in mpc5200 psc i2s driver

Fix missing unsigned for irqsave flags in psc i2s driver
Make attribute visiblity static
Collect all sysfs errors before checking status

[Word wrapped DEVICE_ATTR() lines for 80 columns -- broonie]

Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>