test_cpuid_helpers: Remove test for CPU feature flag upgrades
test_cpuid_helpers: Remove test for CPU feature flag upgrades

The feature flag upgrade mechanism now depends on Xenopsd.
Without a mock for the Xenopsd interface, we can't unit test
these functions.

Signed-off-by: Euan Harris <c3b6e83069c8e9e3af49a38fec6026be89559638@citrix.com>

euanh/xen-api,srowe/xen-api,Frezzle/xen-api,rafalmiel/xen-api,rafalmiel/xen-api,euanh/xen-api,srowe/xen-api,thomassa/xen-api,thomassa/xen-api,euanh/xen-api,srowe/xen-api,thomassa/xen-api,thomassa/xen-api,rafalmiel/xen-api,jjd27/xen-api,euanh/xen-api,Frezzle/xen-api,rafalmiel/xen-api,jjd27/xen-api,srowe/xen-api,Frezzle/xen-api,thomassa/xen-api,rafalmiel/xen-api,Frezzle/xen-api,rafalmiel/xen-api,jjd27/xen-api,thomassa/xen-api,srowe/xen-api,Frezzle/xen-api,jjd27/xen-api,jjd27/xen-api,euanh/xen-api,euanh/xen-api,jjd27/xen-api