xen-pciback: Remove unused function declarations

Commit a92336a ("xen/pciback: Drop two backends, squash and cleanup some code.")
declared but never implemented these functions.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230808150912.43416-1-yuehaibing@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>

Author: Yue Haibing

drivers/xen/xen-pciback/conf_space_quirks.h

@@ -21,8 +21,6 @@ struct xen_pcibk_config_quirk {
 int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field
 				    *field);
 
-int xen_pcibk_config_quirks_remove_field(struct pci_dev *dev, int reg);
-
 int xen_pcibk_config_quirks_init(struct pci_dev *dev);
 
 void xen_pcibk_config_field_free(struct config_field *field);

drivers/xen/xen-pciback/pciback.h

@@ -201,6 +201,3 @@ static inline void xen_pcibk_lateeoi(struct xen_pcibk_device *pdev,
 int xen_pcibk_xenbus_register(void);
 void xen_pcibk_xenbus_unregister(void);
 #endif
-
-/* Handles shared IRQs that can to device domain and control domain. */
-void xen_pcibk_irq_handler(struct pci_dev *dev, int reset);