pinctrl: Increase length of pinmux status buffer

Xilinx ZynqMP SOC can set 6 parameters for its pins. pinmux status
command will print the status of these parameters for each pin. But
current print buffer length is only 40 characters long, increase it
to 80 to print all the parameters.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/3a6be84c8354f38754a9838670cc0319e84f29e8.1645626183.git.michal.simek@xilinx.com