gpio: xilinx: Replace custom variants of bitmap_read()/bitmap_write()

gpio: xilinx: Replace custom variants of bitmap_read()/bitmap_write()

Relatively recently bitmap APIs were expanded by introduction of
bitmap_read() and bitmap_write(). These APIs are generic ones
that may replace custom functions in this driver, i.e. xgpio_get_value32()
and xgpio_set_value32(). Do replace them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250205093200.373709-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>