docs: kvm: convert devices/mpic.txt to ReST

This document is almost in ReST format. The only thing
needed is to mark a list as such and to add an extra
whitespace.

Yet, let's also use the standard document title markup,
as it makes easier if anyone wants later to add sessions
to it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/devices/index.rst

@@ -10,3 +10,4 @@ Devices
    arm-vgic-its
    arm-vgic
    arm-vgic-v3
+   mpic

Documentation/virt/kvm/devices/mpic.rst

@@ -1,9 +1,13 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================
 MPIC interrupt controller
 =========================
 
 Device types supported:
-  KVM_DEV_TYPE_FSL_MPIC_20     Freescale MPIC v2.0
-  KVM_DEV_TYPE_FSL_MPIC_42     Freescale MPIC v4.2
+
+  - KVM_DEV_TYPE_FSL_MPIC_20     Freescale MPIC v2.0
+  - KVM_DEV_TYPE_FSL_MPIC_42     Freescale MPIC v4.2
 
 Only one MPIC instance, of any type, may be instantiated.  The created
 MPIC will act as the system interrupt controller, connecting to each
@@ -12,6 +16,7 @@ vcpu's interrupt inputs.
 Groups:
   KVM_DEV_MPIC_GRP_MISC
    Attributes:
+
     KVM_DEV_MPIC_BASE_ADDR (rw, 64-bit)
       Base address of the 256 KiB MPIC register space.  Must be
       naturally aligned.  A value of zero disables the mapping.