arm/pci: Do not use first PCI IO space bytes for devices

Linux has this convention that the lower 0x1000 bytes of the IO space
should not be used. (cf PCIBIOS_MIN_IO).

Just allocate those bytes to prevent future allocation assigning it to
devices.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>

arm/pci.c

@@ -37,6 +37,9 @@ void pci__arm_init(struct kvm *kvm)
 
 	/* Make PCI port allocation start at a properly aligned address */
 	pci_get_io_port_block(align_pad);
+
+	/* Convention, don't allocate first 0x1000 bytes of PCI IO */
+	pci_get_io_port_block(0x1000);
 }
 
 void pci__generate_fdt_nodes(void *fdt)