dmaengine: idxd: Remove __packed from structures

dmaengine: idxd: Remove __packed from structures

The __packed attribute introduces potential unaligned memory accesses
and endianness portability issues. Instead of relying on compiler-specific
packing, it's much better to explicitly fill structure gaps using padding
fields, ensuring natural alignment.

Since all previously __packed structures already enforce proper alignment
through manual padding, the __packed qualifiers are unnecessary and can be
safely removed.

Signed-off-by: Yi Sun <yi.sun@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Link: https://lore.kernel.org/r/20250404053614.3096769-1-yi.sun@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>