feat(esp-tls): Add unified private key interface via esp_key_config_t

Add ESP_KEY_SOURCE_BUFFER and ESP_KEY_SOURCE_PSA key sources so all
hardware backends (DS, ECDSA, secure element) are accessed via PSA
key IDs through a single esp_tls_cfg_t.client_key field.

components/esp-tls/CMakeLists.txt

@@ -22,7 +22,10 @@ endif()
 idf_component_register(SRCS "${srcs}"
                     INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR} esp-tls-crypto
                     PRIV_INCLUDE_DIRS "private_include"
-                    REQUIRES mbedtls
+                    # mbedtls is public requirements because esp_tls.h
+                    # includes mbedtls header files.
+                    # esp_security is public because esp_tls.h includes esp_key_config.h
+                    REQUIRES mbedtls esp_security
                     PRIV_REQUIRES ${priv_req})
 
 idf_define_esp_err_codes(HEADERS esp_tls_errors.h)
@@ -35,8 +38,3 @@ else()
         target_compile_definitions(${COMPONENT_LIB} PRIVATE ESP_TLS_WITH_LWIP=1)
     endif()
 endif()
-
-
-if(CONFIG_ESP_TLS_USE_SECURE_ELEMENT)
-    idf_component_optional_requires(PRIVATE espressif__esp-cryptoauthlib esp-cryptoauthlib)
-endif()