test: capsule: Remove logic to add public key ESL

The public key EFI Signature List(ESL) needed for capsule
authentication is now embedded into the platform's DTB as part of the
build. Remove the superfluous logic from the test setup.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
diff --git a/test/py/tests/test_efi_capsule/conftest.py b/test/py/tests/test_efi_capsule/conftest.py
index 9160f29..dd41da9 100644
--- a/test/py/tests/test_efi_capsule/conftest.py
+++ b/test/py/tests/test_efi_capsule/conftest.py
@@ -51,22 +51,16 @@
             check_call('cp %s/capsule_pub_key_bad.crt %s/SIGNER2.crt'
                        % (key_dir, data_dir), shell=True)
 
-            # Update dtb adding capsule certificate
-            check_call('cd %s; '
-                       'cp %s/test/py/tests/test_efi_capsule/signature.dts .'
-                       % (data_dir, u_boot_config.source_dir), shell=True)
-            check_call('cd %s; '
-                       'dtc -@ -I dts -O dtb -o signature.dtbo signature.dts; '
-                       'fdtoverlay -i %s/arch/sandbox/dts/test.dtb '
-                            '-o test_sig.dtb signature.dtbo'
-                       % (data_dir, u_boot_config.build_dir), shell=True)
-
         # Update dtb to add the version information
         check_call('cd %s; '
                    'cp %s/test/py/tests/test_efi_capsule/version.dts .'
                    % (data_dir, u_boot_config.source_dir), shell=True)
+
         if capsule_auth_enabled:
             check_call('cd %s; '
+                       'cp %s/arch/sandbox/dts/test.dtb test_sig.dtb'
+                       % (data_dir, u_boot_config.build_dir), shell=True)
+            check_call('cd %s; '
                        'dtc -@ -I dts -O dtb -o version.dtbo version.dts; '
                        'fdtoverlay -i test_sig.dtb '
                             '-o test_ver.dtb version.dtbo'
diff --git a/test/py/tests/test_efi_capsule/signature.dts b/test/py/tests/test_efi_capsule/signature.dts
deleted file mode 100644
index 078cfc7..0000000
--- a/test/py/tests/test_efi_capsule/signature.dts
+++ /dev/null
@@ -1,10 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-
-/dts-v1/;
-/plugin/;
-
-&{/} {
-	signature {
-		capsule-key = /incbin/("SIGNER.esl");
-	};
-};