Revert "x86/platform: Add a wallclock_init func to x86_platforms ops"

This reverts commit cf8ff6b6.

Just found this commit is a function duplicatation of commit 6b617e22
"x86/platform: Add a wallclock_init func to x86_init.timers ops".
Let's revert it and sorry for the noise.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>