Update the description of nucleo U385RG-Q arduino_spi dts

[ulrich-a11-y]

The spi1 node is added and arduino_r3_connector.dtsi is updated.
Fixes: #97543

[github-actions]

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[etienne-lms]

Could you update your P-R with a single commit (no merge commit) to do the expected change?
I think the expected commit message rather look like the one of your 2nd commit:

boards: st: nucleo_u385rg_q: add spi1 node

Configure and enable SPI1 for Arduino connector
and Update arduino_r3_connector accordlingly.

Signed-off-by: ...

By the way, could you use your real anme in your Singeed-off-by tag (and commit authgership) as expected by the DCO instead of your Github account name.

[etienne-lms]

SPI1 inctrl conflicts with already enabled nodes in the board DTS.
I think the SPI/Arduino pin mixung is fully legitimate and the conflicting other nodes should be default disabled and enabled only for the tests and samples where we want them.

dac1 node should be default disabled (in this board DTS file) since its pinctrl state conflicts (pin mux dac1_out1_pa4). For this node, we would need an added DTS overlay file in DAC tests:
tests/drivers/dac/dac_loopback/boards/nucleo_u385rg_q.overlay
and tests/drivers/dac/dac_api/boards/nucleo_u385rg_q.overlay
to explicitly enable dac1 node and disable spi1 node.

Ditto for the i2c3 (pin mux i2c3_scl_pa7). Regarding this node, file ./tests/drivers/i2c/i2c_target_api/boards/nucleo_u385rg_q.overlay should explicitly enable i2c3 node and disable spi1 node.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[ulrich-a11-y]

Thank you, @etienne-lms, for your review. I've closed this PR and opened a new one here:
#98361