soc: qcom: QMI encoding/decoding for big endian

The QMI_DATA_LEN type may have different sizes. Taking the element's
address of that type and interpret it as a smaller sized ones works fine
for little endian platforms but not for big endian ones. Instead use
temporary variables of smaller sized types and cast them correctly to
support big endian platforms.

Signed-off-by: Alexander Wilhelm <alexander.wilhelm@westermo.com>
Fixes: 9b8a11e8 ("soc: qcom: Introduce QMI encoder/decoder")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250522143530.3623809-2-alexander.wilhelm@westermo.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>