[IA64] remove staled comments in asm/system.h
[IA64] remove staled comments in asm/system.h

With the recent optimization made to wrap_mmu_context function,
we don't hold tasklist_lock anymore when wrapping context id.
The comments in asm/system.h must fall through the crack earlier.
Remove staled comments.

I believe it is still beneficial to unlock the runqueue lock
across context switch. So leave __ARCH_WANT_UNLOCKED_CTXSW on.

Signed-off-by: Ken Chen <640d154bafbc821841799e29e14a8064cae56f26@intel.com>
Signed-off-by: Tony Luck <e7984595ec0368ff920a7b3521dc7093683f6f26@intel.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas