KVM: s390: Reworked LCTL and LCTLG instructions

LCTL and LCTLG are also privileged instructions, thus there is no need for
treating them separately from the other instructions in priv.c. So this
patch moves these two instructions to priv.c, adds a check for supervisor
state and simplifies the "handle_eb" instruction decoding by merging the
two eb_handlers jump tables from intercept.c and priv.c into one table only.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>