x86: do not crash on non-Geode PCs in TSC probe

with this fix Geode kernels can be booted (and QA-ed) on generic PCs.

otherwise it crashes and burns during early bootup:

Detected 2160.212 MHz processor.
general protection fault: 0000 [#1]
PREEMPT SMP
Modules linked in:
CPU:    0
EIP:    0060:[<c09071f6>]    Not tainted VLI
EFLAGS: 00010002   (2.6.23-rc9 #90)
EIP is at tsc_init+0xa6/0x150
eax: 00000001   ebx: c1dce000   ecx: 00001900   edx: 00000001
esi: 00051000   edi: 00051000   ebp: c08fdfc4   esp: c08fdfa4
ds: 007b   es: 007b   fs: 00d8  gs: 0000  ss: 0068
Process swapper (pid: 0, ti=c08fc000 task=c082a180 task.ti=c08fc000)
Stack: c076b870 00000870 000000d4 0000001d c0831e80 c1dce000 00051000 00051000
       c08fdfcc c09053f8 c08fdff8 c09045ff 000001e2 c09040a0 00051000 00000020
       0004e500 c0932140 00020800 00099800 c08ed000 01409007 00000000
Call Trace:
 [<c010517a>] show_trace_log_lvl+0x1a/0x30
 [<c0105246>] show_stack_log_lvl+0xb6/0x100
 [<c0105732>] show_registers+0x212/0x3a0
 [<c0105aa4>] die+0x104/0x220
 [<c0105f5f>] do_general_protection+0x1ef/0x2b0
 [<c06699f2>] error_code+0x72/0x78
 [<c09053f8>] time_init+0x8/0x20
 [<c09045ff>] start_kernel+0x1af/0x320
 [<00000000>] 0x0
 =======================
Code: 31 d2 b8 00 00 09 3d f7 35 2c 70 9b c0 a3 04 95 8f c0 e8 ce 4e 99 ff b8 e0 45 93 c0 e8 94 b1 c5 ff e8 7f 3d 80 ff b9 00 19 00 00 <0f> 32 f6 c4 01 74 07 83 25 24 ce 82 c0 fd 8b 0d 20 ce 82 c0 b8
EIP: [<c09071f6>] tsc_init+0xa6/0x150 SS:ESP 0068:c08fdfa4
Kernel panic - not syncing: Attempted to kill the idle task!
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/tsc_32.c

@@ -349,10 +349,10 @@ __cpuinit int unsynchronized_tsc(void)
 
 static void __init check_geode_tsc_reliable(void)
 {
-	unsigned long val;
+	unsigned long res_low, res_high;
 
-	rdmsrl(MSR_GEODE_BUSCONT_CONF0, val);
-	if ((val & RTSC_SUSP))
+	rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
+	if (res_low & RTSC_SUSP)
 		clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
 }
 #else