docs: arm64: booting.rst: get rid of some warnings

Get rid of those warnings:

    Documentation/arm64/booting.rst:253: WARNING: Unexpected indentation.
    Documentation/arm64/booting.rst:259: WARNING: Block quote ends without a blank line; unexpected unindent.

By adding an extra blank lines where needed.

While here, use list markups on some places, as otherwise Sphinx
will consider the next lines as continuation of the privious ones.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/121b267be0a102fde73498c31792e5a9309013cc.1586881715.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/arm64/booting.rst

@@ -173,7 +173,9 @@ Before jumping into the kernel, the following conditions must be met:
 - Caches, MMUs
 
   The MMU must be off.
+
   Instruction cache may be on or off.
+
   The address range corresponding to the loaded kernel image must be
   cleaned to the PoC. In the presence of a system cache or other
   coherent masters with caches enabled, this will typically require
@@ -238,6 +240,7 @@ Before jumping into the kernel, the following conditions must be met:
   - The DT or ACPI tables must describe a GICv2 interrupt controller.
 
   For CPUs with pointer authentication functionality:
+
   - If EL3 is present:
 
     - SCR_EL3.APK (bit 16) must be initialised to 0b1
@@ -249,16 +252,20 @@ Before jumping into the kernel, the following conditions must be met:
     - HCR_EL2.API (bit 41) must be initialised to 0b1
 
   For CPUs with Activity Monitors Unit v1 (AMUv1) extension present:
+
   - If EL3 is present:
-    CPTR_EL3.TAM (bit 30) must be initialised to 0b0
-    CPTR_EL2.TAM (bit 30) must be initialised to 0b0
-    AMCNTENSET0_EL0 must be initialised to 0b1111
-    AMCNTENSET1_EL0 must be initialised to a platform specific value
+
+    - CPTR_EL3.TAM (bit 30) must be initialised to 0b0
+    - CPTR_EL2.TAM (bit 30) must be initialised to 0b0
+    - AMCNTENSET0_EL0 must be initialised to 0b1111
+    - AMCNTENSET1_EL0 must be initialised to a platform specific value
       having 0b1 set for the corresponding bit for each of the auxiliary
       counters present.
+
   - If the kernel is entered at EL1:
-    AMCNTENSET0_EL0 must be initialised to 0b1111
-    AMCNTENSET1_EL0 must be initialised to a platform specific value
+
+    - AMCNTENSET0_EL0 must be initialised to 0b1111
+    - AMCNTENSET1_EL0 must be initialised to a platform specific value
       having 0b1 set for the corresponding bit for each of the auxiliary
       counters present.
 
@@ -304,7 +311,8 @@ following manner:
   Documentation/devicetree/bindings/arm/psci.yaml.
 
 - Secondary CPU general-purpose register settings
-  x0 = 0 (reserved for future use)
-  x1 = 0 (reserved for future use)
-  x2 = 0 (reserved for future use)
-  x3 = 0 (reserved for future use)
+
+  - x0 = 0 (reserved for future use)
+  - x1 = 0 (reserved for future use)
+  - x2 = 0 (reserved for future use)
+  - x3 = 0 (reserved for future use)