spi: nxp-fspi: make const array ls1028a_soc_attr static

Don't populate the const array ls1028a_soc_attr on the stack, instead
make it static. Also makes the object code smaller.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Han Xu <han.xu@nxp.com>
Link: https://lore.kernel.org/r/20221102152904.143423-1-colin.i.king@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>