x86-64/mmcfg: remove __initdata annotation overlooked in 23749:e8d1c8f074ba

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/x86_64/mmconfig_64.c
+++ b/xen/arch/x86/x86_64/mmconfig_64.c
@@ -23,7 +23,7 @@ struct mmcfg_virt {
     char __iomem *virt;
 };
 static struct mmcfg_virt *pci_mmcfg_virt;
-static int __initdata mmcfg_pci_segment_shift;
+static unsigned int mmcfg_pci_segment_shift;
 
 static char __iomem *get_virt(unsigned int seg, unsigned int *bus)
 {