-tip: origin tree build failure

[Ingo Molnar <mingo@elte.hu>]

Today's -tip failed to build because commit 
9e368fa011d4e0aa050db348d69514900520e40b ("ipmi: add PNP discovery (ACPI 
namespace via PNPACPI)") from today's upstream kernel causes the following 
build failure on x86, for CONFIG_ACPI=n && CONFIG_IPMI_SI=y:

 drivers/char/ipmi/ipmi_si_intf.c:3208: error: 'ipmi_pnp_driver' undeclared (first use in this function)
 drivers/char/ipmi/ipmi_si_intf.c:3208: error: (Each undeclared identifier is reported only once
 drivers/char/ipmi/ipmi_si_intf.c:3208: error: for each function it appears in.)
 drivers/char/ipmi/ipmi_si_intf.c:3334: error: 'ipmi_pnp_driver' undeclared (first use in this function)

The reason is that the ipmi_pnp_driver depends on ACPI facilities and is only 
made available under ACPI - while the registration and unregistration is made 
dependent on CONFIG_PNP:

 #ifdef CONFIG_PNP
 	pnp_register_driver(&ipmi_pnp_driver);
 #endif

The solution is to only register this driver under ACPI. (Also, the CONFIG_PNP 
dependency is not needed because pnp_register_driver() is stubbed out in the 
!CONFIG_PNP case.)

I've applied the patch below to tip:out-of-tree for now.

Thanks,

	Ingo

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 679cd08..176f175 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -3204,7 +3204,7 @@ static __devinit int init_ipmi_si(void)
 #ifdef CONFIG_ACPI
 	spmi_find_bmc();
 #endif
-#ifdef CONFIG_PNP
+#ifdef CONFIG_ACPI
 	pnp_register_driver(&ipmi_pnp_driver);
 #endif
 
@@ -3330,7 +3330,7 @@ static __exit void cleanup_ipmi_si(void)
 #ifdef CONFIG_PCI
 	pci_unregister_driver(&ipmi_pci_driver);
 #endif
-#ifdef CONFIG_PNP
+#ifdef CONFIG_ACPI
 	pnp_unregister_driver(&ipmi_pnp_driver);
 #endif