gpio: pca953x: add support for MAX7315

MAX7315 is pin and software compatible with PCA9534, so add it to the I2C
device ID table of pca953x driver.
http://www.datasheetcatalog.org/datasheet/maxim/MAX7315.pdf



Signed-off-by: Alek Du <alek.du@intel.com>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>