PM / devfreq: Remove ARCH_HAS_OPP completely

The Kconfig symbol ARCH_HAS_OPP became redundant in v3.16: commit
049d595a ("PM / OPP: Make OPP invisible to users in Kconfig")
removed the only dependency that used it. Setting it had no effect
anymore.

So commit 78c5e0bb ("PM / OPP: Remove ARCH_HAS_OPP") removed it. For
some reason that commit did not remove all select statements for that
symbol. These statements are now useless. Remove one from devfreq too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>