spi: pxa2xx: Move contents of linux/spi/pxa2xx_spi.h to a local one

There is no user of the linux/spi/pxa2xx_spi.h. Move its contents
to the drivers/spi/spi-pxa2xx.h.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-4-andriy.shevchenko@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>