docs/system/target-arm: Re-alphabetize board list

The board list in target-arm.rst is supposed to be in alphabetical
order by the title text of each file (which is not the same as
alphabetical order by filename).  A few items had got out of order;
correct them.

The entry for
"Facebook Yosemite v3.5 Platform and CraterLake Server (fby35)"
remains out-of-order, because this is not its own file
but is currently part of the aspeed.rst file.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240520141421.1895138-1-peter.maydell@linaro.org

docs/system/target-arm.rst

@@ -86,16 +86,16 @@ undocumented; you can get a complete list by running
    arm/bananapi_m2u.rst
    arm/b-l475e-iot01a.rst
    arm/sabrelite
+   arm/highbank
    arm/digic
    arm/cubieboard
    arm/emcraft-sf2
-   arm/highbank
    arm/musicpal
    arm/gumstix
    arm/mainstone
    arm/kzm
-   arm/nrf
    arm/nseries
+   arm/nrf
    arm/nuvoton
    arm/imx25-pdk
    arm/orangepi
@@ -107,8 +107,8 @@ undocumented; you can get a complete list by running
    arm/stellaris
    arm/stm32
    arm/virt
-   arm/xlnx-versal-virt
    arm/xenpvh
+   arm/xlnx-versal-virt
 
 Emulated CPU architecture support
 =================================