[xpu][test] Port 2 test/prototype/mx_formats/test_{kernels, test_mx_tensor} UT files to intel XPU

[zxd1997066]

For #2917, This PR is targeted to port test/prototype/mx_formats/test_kernels.py and test/prototype/mx_formats/test_mx_tensor.py to intel XPU.

[pytorch-bot]

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[zxd1997066]

cc @liangan1

[vkuzo]

do intel XPUs support mxfp8, mxfp4, nvfp4 formats? If not, I'd say we don't need to add them here?