hw/usb: remove duplicate file in system_ss

Because USB_EHCI_SYSBUS selects USB_EHCI, there is no need to include
hcd-ehci.c explicitly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240223124406.234509-11-pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/usb/meson.build

@@ -18,7 +18,7 @@ system_ss.add(when: 'CONFIG_USB_OHCI_PCI', if_true: files('hcd-ohci-pci.c'))
 system_ss.add(when: 'CONFIG_USB_OHCI_SYSBUS', if_true: files('hcd-ohci-sysbus.c'))
 system_ss.add(when: 'CONFIG_USB_EHCI', if_true: files('hcd-ehci.c'))
 system_ss.add(when: 'CONFIG_USB_EHCI_PCI', if_true: files('hcd-ehci-pci.c'))
-system_ss.add(when: 'CONFIG_USB_EHCI_SYSBUS', if_true: files('hcd-ehci.c', 'hcd-ehci-sysbus.c'))
+system_ss.add(when: 'CONFIG_USB_EHCI_SYSBUS', if_true: files('hcd-ehci-sysbus.c'))
 system_ss.add(when: 'CONFIG_USB_XHCI', if_true: files('hcd-xhci.c'))
 system_ss.add(when: 'CONFIG_USB_XHCI_PCI', if_true: files('hcd-xhci-pci.c'))
 system_ss.add(when: 'CONFIG_USB_XHCI_SYSBUS', if_true: files('hcd-xhci-sysbus.c'))