spi: omap2-mcspi: Disable multi-mode when the previous message kept CS asserted

spi: omap2-mcspi: Disable multi-mode when the previous message kept CS asserted

When the last transfer of a SPI message has the cs_change flag, the CS is kept
asserted after the message.
The next message can't use multi-mode because the CS will be briefly deasserted
before the first transfer.

Remove the early exit of the list_for_each_entry because the last transfer
actually needs to be always checked.

Fixes: d153ff4056cb ("spi: omap2-mcspi: Add support for MULTI-mode")
Signed-off-by: Félix Piédallu <felix.piedallu@non.se.com>
Link: https://patch.msgid.link/20250606-cs_change_fix-v1-2-27191a98a2e5@non.se.com
Signed-off-by: Mark Brown <broonie@kernel.org>