svm: Replace call to svm_load_cr2 with conditional call to svm_trace_vmentry

svm: Replace call to svm_load_cr2 with conditional call to svm_trace_vmentry

Remove the call to svm_load_cr2 (which doesn't do anything useful).
The old svm_load_cr2 is now replaced with a svm_trace_vmentry. A call
to this function is done if "tb_init_done" is non-zero, so we don't call
this unless it's actually being used.

Signed-off-by: Mats Petersson <mats.petersson@amd.com>