i2c(core): fix problems with usage of uintptr

[gen2thomas]

Solved issues and/or description of the change

null reference exception in i2c core drivers when test with test -race, caused by GC - fixed by using an additional parameter for address instead of try to reuse the payload parameter and use a unsafe.Pointer instead of uintptr for the last parameter in test mocks for syscall

this partially fix #1017

Manual test

• OS and Version (Win/Mac/Linux): Linux
• Adaptor(s) and/or driver(s): tinkerboard with PCA9533 and ADS1115

Checklist

• The PR's target branch is 'hybridgroup:dev'
• New and existing unit tests pass locally with my changes (e.g. by run make test)
• No linter errors exist locally (e.g. by run make fmt_check)
• I have performed a self-review of my own code