eal: avoid invalid power intrinsics API usage

eal: avoid invalid power intrinsics API usage

Currently, the API documentation mandates that if the user wants to use
the power management intrinsics, they need to call the
`rte_cpu_get_intrinsics_support` API and check support for specific
intrinsics.

However, if the user does not do that, it is possible to get illegal
instruction error because we're using raw instruction opcodes, which may
or may not be supported at runtime.

Now that we have everything in a C file, we can check for support at
startup and prevent the user from possibly encountering illegal
instruction errors.

We also add return values to the API's as well, because why not.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>