ARM: uniphier: replace <linux/err.h> with <linux/errno.h>

These files only need error number macros.  Actually, IS_ERR(),
PTR_ERR(), ERR_PTR(), etc. are not useful for U-Boot.  Avoid
unnecessary header includes.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>