i2c: i2c-cdns: Detect unsupported sequences for rev 1.0

Revision 1.0 of this IP has a couple of issues, such as not supporting
repeated start conditions for read transfers.

So scan through the list of i2c messages for these conditions
and report an error if they are attempted.

This has been fixed for revision 1.4 of the IP, so only report the error
when the IP can really not do it.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: u-boot@lists.denx.de