bootstd: use ARCH_DMA_MINALIGN in memalign() when allocating memory

Use ARCH_DMA_MINALIGN in memalign() when allocating memory to read the script from the media.

Ref: https://lore.kernel.org/u-boot/CAJaLiFy05F3Cr4X4G2mVkppXnBEFZrHQ+5CngYN8eJPg8ENWkg@mail.gmail.com/T/#m26daadc2463fe653b814a94e6309e5e6bb6be1d1

Note: this patch depends on the previous patch
https://patchwork.ozlabs.org/project/uboot/patch/20230917230649.30357-1-mibodhi@gmail.com/



Signed-off-by: Tony Dinh <mibodhi@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>