ACPI / LPSS: Make PCI dependency explicit

After commit 5d32a665 (PCI/ACPI: Allow ACPI to be built without
CONFIG_PCI set), it is possible to build ACPI without any PCI support.

This code depends on PCI. Compile only when PCI is present.

Fixes: 5d32a665 ("PCI/ACPI: Allow ACPI to be built without CONFIG_PCI set")
Signed-off-by: Sinan Kaya <okaya@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/Makefile

@@ -41,7 +41,8 @@ acpi-y				+= ec.o
 acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
 acpi-$(CONFIG_PCI)		+= pci_root.o pci_link.o pci_irq.o
 obj-$(CONFIG_ACPI_MCFG)		+= pci_mcfg.o
-acpi-y				+= acpi_lpss.o acpi_apd.o
+acpi-$(CONFIG_PCI)		+= acpi_lpss.o
+acpi-y				+= acpi_apd.o
 acpi-y				+= acpi_platform.o
 acpi-y				+= acpi_pnp.o
 acpi-$(CONFIG_ARM_AMBA)	+= acpi_amba.o

drivers/acpi/internal.h

@@ -81,7 +81,11 @@ void acpi_debugfs_init(void);
 #else
 static inline void acpi_debugfs_init(void) { return; }
 #endif
+#ifdef CONFIG_PCI
 void acpi_lpss_init(void);
+#else
+static inline void acpi_lpss_init(void) {}
+#endif
 
 void acpi_apd_init(void);