package/linux-headers: drop 5.17.x option

The 5.17.x series is now EOL upstream, so drop the linux-headers option and
add legacy handling for it.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

Config.in.legacy

@@ -146,6 +146,13 @@ endif
 
 comment "Legacy options removed in 2022.11"
 
+config BR2_KERNEL_HEADERS_5_17
+	bool "kernel headers version 5.17.x are no longer supported"
+	select BR2_LEGACY
+	help
+	  Version 5.17.x of the Linux kernel headers are no longer
+	  maintained upstream and are now removed.
+
 config BR2_iwmmxt
 	bool "ARM iwmmxt variant removed"
 	select BR2_LEGACY

package/linux-headers/Config.in.host

@@ -53,10 +53,6 @@ config BR2_KERNEL_HEADERS_5_15
 	bool "Linux 5.15.x kernel headers"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_15
 
-config BR2_KERNEL_HEADERS_5_17
-	bool "Linux 5.17.x kernel headers"
-	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_17
-
 config BR2_KERNEL_HEADERS_5_19
 	bool "Linux 5.19.x kernel headers"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_19
@@ -402,7 +398,6 @@ config BR2_DEFAULT_KERNEL_HEADERS
 	default "5.4.212"	if BR2_KERNEL_HEADERS_5_4
 	default "5.10.142"	if BR2_KERNEL_HEADERS_5_10
 	default "5.15.67"	if BR2_KERNEL_HEADERS_5_15
-	default "5.17.15"	if BR2_KERNEL_HEADERS_5_17
 	default "5.19.13"	if BR2_KERNEL_HEADERS_5_19
 	default "6.0"		if BR2_KERNEL_HEADERS_6_0
 	default BR2_DEFAULT_KERNEL_VERSION if BR2_KERNEL_HEADERS_VERSION