cmake/sysbuild/b0_mcuboot_signing: fixed signing with PURE signature

Fix typo in Kconfig property check. Image was signed always as for
a pre-hashed signature which caused that this didn't work for
PURE ED25519.

Signed-off-by: Andrzej Puzdrowski <[email protected]>
(cherry picked from commit 73186d5)

Author: nvlsianpu

cmake/sysbuild/b0_mcuboot_signing.cmake

@@ -48,7 +48,7 @@ function(ncs_secure_boot_mcuboot_sign application bin_files signed_targets prefi
   set(encrypted_args)
 
   if(SB_CONFIG_SOC_SERIES_NRF54LX AND SB_CONFIG_BOOT_SIGNATURE_TYPE_ED25519)
-    if(NOT SB_CONFIG_SB_CONFIG_BOOT_SIGNATURE_TYPE_PURE)
+    if(NOT SB_CONFIG_BOOT_SIGNATURE_TYPE_PURE)
       set(imgtool_extra --sha 512 ${imgtool_extra})
     else()
       set(imgtool_extra --pure ${imgtool_extra})