radio: iris: Use kernel API to copy data from user space

Use copy_from_user kernel api to copy any data from user space
to kernel space.

Change-Id: Ia3b7bb0f98180bd8792c1c18e930cb5609b8dc82
CRs-Fixed: 540320
Signed-off-by: Ayaz Ahmad <aahmad@codeaurora.org>