[media] ir-hix5hd2: remove writel/readl_relaxed define

Commit 9439eb3a ("asm-generic: io: implement relaxed
accessor macros as conditional wrappers") has added
{read,write}{b,w,l,q}_relaxed to include/asm-generic/io.h

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>