linux: change CIP kernel download method

Downloading from https a tarball is faster than cloning a git repo.
If needed, BR2_LINUX_KERNEL_CUSTOM_GIT can be used as a fallback
mechanism to downlad the CIP kernel with git.

Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

linux/Config.in

@@ -35,7 +35,7 @@ config BR2_LINUX_KERNEL_LATEST_VERSION
 	bool "Latest version (5.3)"
 
 config BR2_LINUX_KERNEL_LATEST_CIP_VERSION
-	bool "Latest CIP SLTS version (v4.19.75-cip11)"
+	bool "Latest CIP SLTS version (4.19.75-cip11)"
 	help
 	  CIP launched in the spring of 2016 to address the needs of
 	  organizations in industries such as power generation and
@@ -123,7 +123,7 @@ endif
 config BR2_LINUX_KERNEL_VERSION
 	string
 	default "5.3.8" if BR2_LINUX_KERNEL_LATEST_VERSION
-	default "v4.19.75-cip11" if BR2_LINUX_KERNEL_LATEST_CIP_VERSION
+	default "4.19.75-cip11" if BR2_LINUX_KERNEL_LATEST_CIP_VERSION
 	default BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE \
 		if BR2_LINUX_KERNEL_CUSTOM_VERSION
 	default "custom" if BR2_LINUX_KERNEL_CUSTOM_TARBALL

linux/linux.mk

@@ -30,7 +30,8 @@ else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_SVN),y)
 LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
 LINUX_SITE_METHOD = svn
 else ifeq ($(BR2_LINUX_KERNEL_LATEST_CIP_VERSION),y)
-LINUX_SITE = git://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git
+LINUX_SOURCE = linux-cip-$(LINUX_VERSION).tar.gz
+LINUX_SITE = https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/snapshot
 else ifneq ($(findstring -rc,$(LINUX_VERSION)),)
 # Since 4.12-rc1, -rc kernels are generated from cgit. This also works for
 # older -rc kernels.