[init] Move PCIe probing to srv.init

This was kept in the kernel as a way to keep exercising the code, but it
doesn't belong there. This moves it to init, which doesn't do anything
but probe for devices currently - but at least it's executing the code
in userspace now.

src/libraries/bootproto/bootproto.module

@@ -3,6 +3,7 @@
 bp = module("bootproto",
     kind = "lib",
     public_headers = [
+        "bootproto/acpi.h",
         "bootproto/bootconfig.h",
         "bootproto/devices/framebuffer.h",
         "bootproto/init.h",