PCI: Only build PCI syscalls on architectures that want them

The PCI syscalls are built on every architecture except X86, but only
a few have ever hooked them up.  Use a new Kconfig symbol to save a
couple of kB on the architectures that have never used the syscalls.
Tested on x86 and ia64 only.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 79c6e5a..2a85dc3 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -327,6 +327,9 @@
 	bool
 	default y
 
+config PCI_SYSCALL
+	def_bool PCI
+
 config ALPHA_CORE_AGP
 	bool
 	depends on ALPHA_GENERIC || ALPHA_TITAN || ALPHA_MARVEL