Problem compiling drm-current-kmod

Good morning,                        my system:[root_at_STING /usr/ports/graphics/drm-current-kmod]# uname -a
FreeBSD STING 13.0-CURRENT FreeBSD 13.0-CURRENT #16 main-c255860-g2903606b606: Tue Jan 12 04:59:16 CET 2021     root_at_STING:/usr/obj/usr/src/amd64.amd64/sys/STING  amd64

I get the following error while trying to upgrade drm-current-kmod from ports:/usr/ports/graphics/drm-current-kmod/work/drm-kmod-drm_v5.4.62_6/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:4009:6: error: implicit declaration of function 'pci_is_root_bus' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
        if (pci_is_root_bus(adev->pdev->bus)) {
            ^
/usr/ports/graphics/drm-current-kmod/work/drm-kmod-drm_v5.4.62_6/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:4009:6: note: did you mean 'pci_set_bus'?
/usr/src/sys/dev/pci/pcivar.h:385:1: note: 'pci_set_bus' declared here
PCI_ACCESSOR(bus,               BUS,            uint8_t)
^
/usr/src/sys/dev/pci/pcivar.h:371:2: note: expanded from macro 'PCI_ACCESSOR'
        __BUS_ACCESSOR(pci, var, PCI, ivar, type)
        ^
/usr/src/sys/sys/bus.h:812:22: note: expanded from macro '__BUS_ACCESSOR'
static __inline void varp ## _set_ ## var(device_t dev, type t)         \
                     ^
<scratch space>:77:1: note: expanded from here
pci_set_bus
^
1 error generated.*** Error code 1

Stop.
make[4]: stopped in /usr/ports/graphics/drm-current-kmod/work/drm-kmod-drm_v5.4.62_6/amd/amdgpu
*** Error code 1
*** Error code 1
*** Error code 1

Stop.
make[1]: stopped in /usr/ports/graphics/drm-current-kmod
*** Error code 1

Stop.
make: stopped in /usr/ports/graphics/drm-current-kmod

Filippo