Commit 097d88e9 ("gpio: xilinx: use gpiochip data pointer") replaces
the use of container_of() with gpiochip_get_data(). Unfortunately, the
data pointer is not yet set by the time xgpio_save_regs() is called,
causing a system hang.

Fixes: 097d88e9 ("gpio: xilinx: use gpiochip data pointer")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>