doc: board: ti: k3 docs: Use ::prompt

Use prompt instead of code-block to have copy-paste friendly command
documentation.

Signed-off-by: Nishanth Menon <nm@ti.com>
diff --git a/doc/board/ti/am62x_sk.rst b/doc/board/ti/am62x_sk.rst
index 4703ce6..b12dc85 100644
--- a/doc/board/ti/am62x_sk.rst
+++ b/doc/board/ti/am62x_sk.rst
@@ -76,15 +76,15 @@
 .. include::  ../ti/k3.rst
     :start-after: .. k3_rst_include_start_common_env_vars_defn
     :end-before: .. k3_rst_include_end_common_env_vars_defn
-.. code-block:: bash
+.. prompt:: bash $
 
- $ export UBOOT_CFG_CORTEXR=am62x_evm_r5_defconfig
- $ export UBOOT_CFG_CORTEXA=am62x_evm_a53_defconfig
- $ export TFA_BOARD=lite
- $ # we dont use any extra TFA parameters
- $ unset TFA_EXTRA_ARGS
- $ export OPTEE_PLATFORM=k3-am62x
- $ export OPTEE_EXTRA_ARGS="CFG_WITH_SOFTWARE_PRNG=y"
+  export UBOOT_CFG_CORTEXR=am62x_evm_r5_defconfig
+  export UBOOT_CFG_CORTEXA=am62x_evm_a53_defconfig
+  export TFA_BOARD=lite
+  # we dont use any extra TFA parameters
+  unset TFA_EXTRA_ARGS
+  export OPTEE_PLATFORM=k3-am62x
+  export OPTEE_EXTRA_ARGS="CFG_WITH_SOFTWARE_PRNG=y"
 
 .. am62x_evm_rst_include_start_build_steps
 
@@ -271,6 +271,6 @@
 
 To start OpenOCD and connect to the board
 
-.. code-block:: bash
+.. prompt:: bash $
 
   openocd -f board/ti_am625evm.cfg