p54spi: Update kconfig help text

This updates the p54spi Kconfig help text.
The driver works well on n8x0, so remove the words "experimental" and "untested".

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 file changed