pinctrl: cy8c95x0: Move driver data to the local variable in ->probe()

pinctrl: cy8c95x0: Move driver data to the local variable in ->probe()

For all these years of driver existence the driver_data has been used
only as a raw material for other fields in the struct cy8c95x0_pinctrl.
Move it from the structure to be just a local variable in ->probe().
Later, if ever need arises, we may reconsider that.

While at it, drop an unneeded validation and replace uintptr_t with plain
unsigned long which is more readable and works in the same way.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>