hw/net/can/xlnx-versal-canfd: Fix sorting of the tx queue

hw/net/can/xlnx-versal-canfd: Fix sorting of the tx queue

Returning an uint32_t casted to a gint from g_cmp_ids causes the tx queue to
become wrongly sorted when executing g_slist_sort. Fix this by always
returning -1 or 1 from g_cmp_ids based on the ID comparison instead.
Also, if two message IDs are the same, sort them by using their index and
transmit the message at the lowest index first.

Signed-off-by: Shiva sagar Myana <Shivasagar.Myana@amd.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Message-id: 20240603051732.3334571-1-Shivasagar.Myana@amd.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>