ARM: uniphier: drop weird sizeof()

My intention was to ioremap a 4-byte register.  Coincidentally enough,
sizeof(SZ_4) equals to SZ_4, but this code is weird anyway.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Olof Johansson <olof@lixom.net>