docs: kvm: convert arm/hyp-abi.txt to ReST

- Add proper markups for titles;
- Adjust whitespaces and blank lines to match ReST
  needs;
- Mark literal blocks as such.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/arm/hyp-abi.txt → Documentation/virt/kvm/arm/hyp-abi.rst

-* Internal ABI between the kernel and HYP
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================================
+Internal ABI between the kernel and HYP
+=======================================
 
 This file documents the interaction between the Linux kernel and the
 hypervisor layer when running Linux as a hypervisor (for example
@@ -19,7 +23,9 @@ and only act on individual CPUs.
 Unless specified otherwise, any built-in hypervisor must implement
 these functions (see arch/arm{,64}/include/asm/virt.h):
 
-* r0/x0 = HVC_SET_VECTORS
+* ::
+
+    r0/x0 = HVC_SET_VECTORS
     r1/x1 = vectors
 
   Set HVBAR/VBAR_EL2 to 'vectors' to enable a hypervisor. 'vectors'
@@ -27,13 +33,17 @@ these functions (see arch/arm{,64}/include/asm/virt.h):
   of the architecture. Only implemented by the initial stubs, not by
   Linux hypervisors.
 
-* r0/x0 = HVC_RESET_VECTORS
+* ::
+
+    r0/x0 = HVC_RESET_VECTORS
 
   Turn HYP/EL2 MMU off, and reset HVBAR/VBAR_EL2 to the initials
   stubs' exception vector value. This effectively disables an existing
   hypervisor.
 
-* r0/x0 = HVC_SOFT_RESTART
+* ::
+
+    r0/x0 = HVC_SOFT_RESTART
     r1/x1 = restart address
     x2 = x0's value when entering the next payload (arm64)
     x3 = x1's value when entering the next payload (arm64)

Documentation/virt/kvm/arm/index.rst

@@ -7,4 +7,5 @@ ARM
 .. toctree::
    :maxdepth: 2
 
+   hyp-abi
    pvtime