leds: pca953x: Use of_device_get_match_data()

This driver can use the of_device_get_match_data() API to simplify the
code. Replace calls to of_match_device() with this newer API under the
assumption that where it is called will be when we know the device is
backed by a DT node. This nicely avoids referencing the match table when
it is undefined with configurations where CONFIG_OF=n.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Dan Murphy <dmurphy@ti.com>
Cc: <linux-leds@vger.kernel.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>