initial buildroot for linux 5.15

package/json-c/Config.in

@@ -0,0 +1,13 @@
+config BR2_PACKAGE_JSON_C
+	bool "json-c"
+	# uses __sync_val_compare_and_swap_4
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
+	help
+	  JSON-C - A JSON implementation in C
+
+	  JSON-C implements a reference counting object model that
+	  allows you to easily construct JSON objects in C, output
+	  them as JSON formatted strings and parse JSON formatted
+	  strings back into the C representation of JSON objects.
+
+	  https://github.com/json-c/json-c/

package/json-c/json-c.hash

@@ -0,0 +1,4 @@
+# From https://github.com/json-c/json-c/wiki
+sha256  b8d80a1ddb718b3ba7492916237bbf86609e9709fb007e7f7d4322f02341a4c6  json-c-0.15.tar.gz
+# Locally calculated
+sha256  74c1e6ca5eba76b54d0ad00d4815c8315c1b3bc45ff99de61d103dc92486284c  COPYING

package/json-c/json-c.mk

@@ -0,0 +1,15 @@
+################################################################################
+#
+# json-c
+#
+################################################################################
+
+JSON_C_VERSION = 0.15
+JSON_C_SITE = https://s3.amazonaws.com/json-c_releases/releases
+JSON_C_INSTALL_STAGING = YES
+JSON_C_LICENSE = MIT
+JSON_C_LICENSE_FILES = COPYING
+JSON_C_CPE_ID_VENDOR = json-c_project
+
+$(eval $(cmake-package))
+$(eval $(host-cmake-package))