hw/sd: ssi-sd: Support multiple block write

hw/sd: ssi-sd: Support multiple block write

For a multiple block write operation, each block begins with a multi
write start token. Unlike the SD mode that the multiple block write
ends when receiving a STOP_TRAN command (CMD12), a special stop tran
token is used to signal the card.

Emulating this by manually sending a CMD12 to the SD card core, to
bring it out of the receiving data state.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210128063035.15674-7-bmeng.cn@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>