firmware: arm_ffa: Set dma_mask for ffa devices
In the Linux kernel, the following vulnerability has been resolved:

firmware: arm_ffa: Set dma_mask for ffa devices

Set dma_mask for FFA devices, otherwise DMA allocation using the device pointer
lead to following warning:

WARNING: CPU: 1 PID: 1 at kernel/dma/mapping.c:597 dma_alloc_attrs+0xe0/0x124