i2c: ocores: fix polling mode workaround on FU540-C000 SoC

The FU540-C000 has a broken IRQ and support was added earlier
so that it will operate in polling mode, but seems to work only
in case interrupts property is missing from the i2c0 dt-node.
This should not be the case and the driver should handle polling
mode with the interrupt property present in i2c0 node of the
device tree.
So check if it's the FU540-C000 soc and enable polling mode master
xfers, as the IRQ for this chip is broken.

Fixes commit c45d4ba8 ("i2c: ocores: add polling mode workaround
for Sifive FU540-C000 SoC")

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>