The single block read (CMD17) codes are the same as the multiple
block read (CMD18). Merge them into one. The same applies to single
block write (CMD24) and multiple block write (CMD25).

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: <20210128063035.15674-3-bmeng.cn@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>