asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr()

asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr()

The asm-generic/io.h already has default definition, remove unnecessary
arch's defination.

Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@quicinc.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>