Without this commit the block read from non-block register could cause
the system to hang. The first read byte is interpreted as block length.
Which for non-block transfers is not true.
For example read of UPTIME_SECS of Monimod register could hang the system:
i2cdump -y 0x9 0x12 s 0xd7
Signed-off-by: Adam Wujek <dev_public@wujek.eu>