x86: pmu: fix failures on 32-bit due to wrong masks

Some mask computation are using long constants instead of long long
constants, which causes test failures on x86-32.

Signed-off-by: Nadav Amit <namit@vmware.com>
Message-Id: <20200619193909.18949-1-namit@vmware.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>