Directly return -ENOTTY in rpmsgxxx_ioctl() when the command is
not supported to avoid fdsan command FIOC_SETTAG and FIOC_GETTAG
pass to the rpmsg dev/mtd/blk server with CONFIG_FDSAN enabled.
Signed-off-by: wangbowen6 <wangbowen6@xiaomi.com>
Like rpmsgdev and rpmsgmtd, rpmsgblk allow the local cpu to
access the block device in the remote cpu.
Signed-off-by: wangbowen6 <wangbowen6@xiaomi.com>