Also use default defintions for PKG_SOURCE_SUBDIR, PKG_SOURCE

Signed-off-by: Felix Fietkau <nbd@nbd.name>

Replace *MD5SUM with *HASH, replace MD5 hashes with SHA256

Signed-off-by: Felix Fietkau <nbd@nbd.name>

sparse-0.5.0 won't link against lvm 3.5.0 as "llvm-config --libs" does not
include system libs like pthreads. This problem got fixed but not released
yet, so we need to fetch from their git repo.

Signed-off-by: Stefan Sydow <stefan.sydow@tu-berlin.de>

This change does multiple things, all related to enable sparse usage as
a static analysis tool selectable from the OpenWrt configuration:
*add a KERNEL_SPARSE option in the config to add sparse to the kernel
 build (through the C=1 option usage)
*add sparse as a new host tools. It will get selected automatically when
 the above option will be enabled

Signed-off-by: Mathieu Olivari <mathieu@qca.qualcomm.com>

SVN-Revision: 40490