PCI/ASPM: Always build aspm.c

Some ASPM-related tasks, such as save and restore of LTR and L1SS
capabilities, still need to be performed when CONFIG_PCIEASPM is not
enabled. To prepare for these changes, wrap the current code in aspm.c
with an #ifdef and always build the file.

Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@linux.intel.com
[bhelgaas: split build change from function moves]
Link: https://lore.kernel.org/r/20240223205851.114931-3-helgaas@kernel.orgSigned-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pcie/Makefile

@@ -6,7 +6,7 @@ pcieportdrv-y			:= portdrv.o rcec.o
 
 obj-$(CONFIG_PCIEPORTBUS)	+= pcieportdrv.o
 
-obj-$(CONFIG_PCIEASPM)		+= aspm.o
+obj-y				+= aspm.o
 obj-$(CONFIG_PCIEAER)		+= aer.o err.o
 obj-$(CONFIG_PCIEAER_INJECT)	+= aer_inject.o
 obj-$(CONFIG_PCIE_PME)		+= pme.o

drivers/pci/pcie/aspm.c

@@ -24,6 +24,8 @@
 
 #include "../pci.h"
 
+#ifdef CONFIG_PCIEASPM
+
 #ifdef MODULE_PARAM_PREFIX
 #undef MODULE_PARAM_PREFIX
 #endif
@@ -1517,3 +1519,5 @@ bool pcie_aspm_support_enabled(void)
 {
 	return aspm_support_enabled;
 }
+
+#endif /* CONFIG_PCIEASPM */