mctp: i2c: Use named initializers for struct i2c_device_id

mctp: i2c: Use named initializers for struct i2c_device_id

While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.

This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.

While touching this array, unify usage of whitespace in the list
terminator to what most other arrays are using.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20260519153613.1594429-2-u.kleine-koenig@baylibre.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>