KVM: x86/pmu: Rename reprogram_counters() to clarify usage

KVM: x86/pmu: Rename reprogram_counters() to clarify usage

Rename reprogram_counters() to kvm_pmu_request_counters_reprogram()
clarifying that it is more similar to
kvm_pmu_request_counter_reprogram(), and less similar to
reprogram_counter(). The kvm_pmu_* prefix is also appropriate as the
function is exposed in the header.

Opportunistically rename the argument from 'diff' to 'counters'.

No functional change intended.

Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260527234711.4175166-7-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>