documentation: Fix evaluation of reStructuredText

eval_rst isn't a valid directive. Use eval-rst instead. Also, add curly
braces where necessary since the MyST parser requires them.

Change-Id: I68337354e9bd4de4b2c29d4e42c3bb22337fbe06
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83117
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>

Documentation/mainboard/hp/8560w.md

@@ -17,7 +17,7 @@ clip to read and flash the chip.
 
 ![8560w_chip_location](8560w_flash.webp)
 
-```eval_rst
+```{eval-rst}
 +---------------------+------------+
 | Type                | Value      |
 +=====================+============+
@@ -61,7 +61,7 @@ clip to read and flash the chip.
 
 ## Technology
 
-```eval_rst
+```{eval-rst}
 +------------------+--------------------------------------------------+
 | Northbridge      | :doc:`../../northbridge/intel/sandybridge/index` |
 +------------------+--------------------------------------------------+

Documentation/mainboard/hp/pro_3500_series.md

@@ -14,7 +14,7 @@ therefore the automatic fan control will not increase the fan speed.
 
 ## Flashing coreboot
 
-```{eval_rst}
+```{eval-rst}
 +---------------------+-------------------------+
 | Type                | Value                   |
 +=====================+=========================+
@@ -82,7 +82,7 @@ until cleanly power cycled.
 
 ## Technology
 
-```{eval_rst}
+```{eval-rst}
 +------------------+--------------------------------------------------+
 | Northbridge      | :doc:`../../northbridge/intel/sandybridge/index` |
 +------------------+--------------------------------------------------+