arm/xen: Drop the definition of xen_pci_platform_unplug
arm/xen: Drop the definition of xen_pci_platform_unplug

The commit 6f6c15ef912465b3aaafe709f39bd6026a8b3e72 "xen/pvhvm: Remove
the xen_platform_pci int." makes the x86 version of
xen_pci_platform_unplug static.

Therefore we don't need anymore to define a dummy xen_pci_platform_unplug
for ARM.

Signed-off-by: Julien Grall <2fe41d4e32b0bb991f63b975f2bed08c1e666665@citrix.com>
Signed-off-by: Stefano Stabellini <22a0c6385d750d07aa383c9f813cf6f0228657d8@eu.citrix.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs