spi: pxa2xx: Fix regression when toggling chip select on LPSS devices

spi: pxa2xx: Fix regression when toggling chip select on LPSS devices

The commit 78b435c9044a ("spi: pxa2xx: Introduce __lpss_ssp_update_priv()
helper") broke speaker output on my ASUS UX5304MA laptop. The problem is
in inverted value that got written in the private register.

Simple bug, simple fix.

Fixes: 78b435c9044a ("spi: pxa2xx: Introduce __lpss_ssp_update_priv() helper")
Signed-off-by: Mark Lord <mlord@pobox.com>
Tested-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20250204174506.149978-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>