rtw89: 8852c: disable dma during mac init

Without this patch, our hardware attempts to perform dma while device
cpu restarts, and leads to iommu page faults caused by invalid requests.
Some platforms show warning messages as below:
rtw89_8852ce 0000:01:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT
domain=0x000a address=0x10000000004 flags=0x0030]

Signed-off-by: Po-Hao Huang <phhuang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220704023453.19935-2-pkshih@realtek.com