x86: get x86_phys_bits early

when try to make hpet_enable use io_remap instead fixmap got

ioremap: invalid physical address fed00000
------------[ cut here ]------------
WARNING: at arch/x86/mm/ioremap.c:161 __ioremap_caller+0x8c/0x2f3()
Modules linked in:
Pid: 0, comm: swapper Not tainted 2.6.26-rc9-tip-01873-ga9827e7-dirty #358

Call Trace:
 [<ffffffff8026615e>] warn_on_slowpath+0x6c/0xa7
 [<ffffffff802e2313>] ? __slab_alloc+0x20a/0x3fb
 [<ffffffff802d85c5>] ? mpol_new+0x88/0x17d
 [<ffffffff8022a4f4>] ? mcount_call+0x5/0x31
 [<ffffffff8022a4f4>] ? mcount_call+0x5/0x31
 [<ffffffff8024b0d2>] __ioremap_caller+0x8c/0x2f3
 [<ffffffff80e86dbd>] ? hpet_enable+0x39/0x241
 [<ffffffff8022a4f4>] ? mcount_call+0x5/0x31
 [<ffffffff8024b466>] ioremap_nocache+0x2a/0x40
 [<ffffffff80e86dbd>] hpet_enable+0x39/0x241
 [<ffffffff80e7a1f6>] hpet_time_init+0x21/0x4e
 [<ffffffff80e730e9>] start_kernel+0x302/0x395
 [<ffffffff80e722aa>] x86_64_start_reservations+0xb9/0xd4
 [<ffffffff80e722fe>] ? x86_64_init_pda+0x39/0x4f
 [<ffffffff80e72400>] x86_64_start_kernel+0xec/0x107

---[ end trace a7919e7f17c0a725 ]---

it seems for amd system that is set later...
try to move setting early in early_identify_cpu.
and remove same code for intel and centaur.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>