package/linux-headers: add support for Linux 5.0 kernel headers

This sets 5.0 to be the default, moving from 4.19 which was used instead
of 4.20 for the LTS branch.

We need to update linux/linux.hash as part of this commit, because
package/linux-headers/linux-headers.hash is a symlink to
linux/linux.hash.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

linux/linux.hash

@@ -1,3 +1,5 @@
+# From https://www.kernel.org/pub/linux/kernel/v5.x/sha256sums.asc
+sha256 43bfea3a6b24b4e5f63190409a199bee8cb93dbea01c52ad7f017078ebdf7c9b  linux-5.0.2.tar.xz
 # From https://www.kernel.org/pub/linux/kernel/v4.x/sha256sums.asc
 sha256 1cf544308195250805e0731c716691bea4c1ed29e03e6f9ae5be6dc16785a504  linux-4.20.12.tar.xz
 sha256 7ec71d90d6e96e6f741676d157ac06f30c75be4eaf1649143a3c8b7d4f919731  linux-4.19.25.tar.xz

package/linux-headers/Config.in.host

@@ -6,9 +6,7 @@ config BR2_PACKAGE_HOST_LINUX_HEADERS
 choice
 	prompt "Kernel Headers"
 	default BR2_KERNEL_HEADERS_AS_KERNEL if BR2_LINUX_KERNEL
-	# We are intentionally staying at 4.19 for the next Buildroot
-	# LTS release (2019.02)
-	default BR2_KERNEL_HEADERS_4_19
+	default BR2_KERNEL_HEADERS_5_0
 	help
 	  Select the kernel version to get headers from.
 
@@ -51,6 +49,10 @@ config BR2_KERNEL_HEADERS_4_20
 	bool "Linux 4.20.x kernel headers"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_20
 
+config BR2_KERNEL_HEADERS_5_0
+	bool "Linux 5.0.x kernel headers"
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0
+
 config BR2_KERNEL_HEADERS_VERSION
 	bool "Manually specified Linux version"
 	help
@@ -116,6 +118,10 @@ choice
 	  This is used to hide/show some packages that have strict
 	  requirements on the version of kernel headers.
 
+config BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_0
+	bool "5.0.x"
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0
+
 config BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_20
 	bool "4.20.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_20
@@ -292,6 +298,7 @@ config BR2_DEFAULT_KERNEL_HEADERS
 	default "4.14.103"	if BR2_KERNEL_HEADERS_4_14
 	default "4.19.25"	if BR2_KERNEL_HEADERS_4_19
 	default "4.20.12"	if BR2_KERNEL_HEADERS_4_20
+	default "5.0.2"		if BR2_KERNEL_HEADERS_5_0
 	default BR2_DEFAULT_KERNEL_VERSION if BR2_KERNEL_HEADERS_VERSION
 	default "custom"	if BR2_KERNEL_HEADERS_CUSTOM_TARBALL
 	default BR2_KERNEL_HEADERS_CUSTOM_REPO_VERSION \