ARM: uniphier: replace <common.h> with <linux/delay.h> in pll settings

ARM: uniphier: replace <common.h> with <linux/delay.h> in pll settings

The #include <common.h> was added for mdelay().  Later, the declaration
of mdelay was moved to <linux/delay.h> by commit 5bc516ed661a ("delay:
collect {m, n, u}delay declarations to include/linux/delay.h").

There is no need to include <common.h> now.

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