qcom: peripheral-loader: Use iowrite32_copy instead of writeq

Due to stricter alignment restrictions on arm64 targets,
replace the use of writeq with iowrite32_copy to prevent
alignment exceptions while accessing device memory. The
specific access that fails here is an 8byte store to an
address that is not 8 byte aligned.

Change-Id: Ia55ecde572a4f1fa46c3aea5f08db4c5637404c4
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>