kernel: Drop non-standard GNU inline assignment syntax

* We needed this previously due to our gcc2 compiled kernel.
* Now that our kernel is always latest gcc, we can move to the
c++20 syntax for inline assignment.
* Improves compatibility with clang, less GNU-specific stuff

Change-Id: Ib7272a0a52554a31e9a0e788fd3f031db9049795
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5898
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

i2c: add device names

Change-Id: I1cb40223cdb43cc7069aee382657aac2b4cfd62b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2481
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

i2c: bus manager

Change-Id: Ic2a7d3a4949a06a6e5f35dbb0b43d8239f92a370
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2457
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: Rene Gollent <rene@gollent.com>