vchiq: fix build with clang 21
When compiling vchiq with clang 21, the following -Werror warning is
produced:
sys/contrib/vchiq/interface/vchiq_arm/vchiq_arm.c:728:27: error: default initialization of an object of type 'VCHIQ_QUEUE_MESSAGE32_T' with const member leaves the object uninitialized [-Werror,-Wdefault-const-init-field-unsafe]
728 | VCHIQ_QUEUE_MESSAGE32_T args32;
| ^
sys/contrib/vchiq/interface/vchiq_arm/vchiq_ioctl.h:151:40: note: member 'elements' declared 'const' here
151 | const /*VCHIQ_ELEMENT_T * */ uint32_t elements;
| ^While the warning is formally correct, the 'args32' object is
immediately initialized after its declaration. Therefore, suppress the
warning.
MFC after: 3 days