wifi: rtw89: add IO offload support via firmware

wifi: rtw89: add IO offload support via firmware

Offload register write operations to the firmware to improve IO efficiency.
Instead of the host performing direct bus access for every register, the
operations are now encapsulated into firmware commands.

This implementation allows the host to aggregate multiple register write
actions into a single command buffer. By batching these operations, we
reduce the number of individual transactions on the bus and minimize
per-transfer overhead, leading to faster overall IO performance.

Add a support_fw_cmd_ofld field to the chip_info structure to control
whether firmware-offloaded batch writes are enabled. Enable it by
default for RTL8832CU.

Co-developed-by: Eric Huang <echuang@realtek.com>
Signed-off-by: Eric Huang <echuang@realtek.com>
Co-developed-by: Johnson Tsai <wenjie.tsai@realtek.com>
Signed-off-by: Johnson Tsai <wenjie.tsai@realtek.com>
Signed-off-by: Chia-Yuan Li <leo.li@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20260420034051.17666-9-pkshih@realtek.com