bitbake.conf: Set vardepvalue for PARALLEL_MAKEINST
If you leave PARALLEL_MAKEINST at its default from PARALLEL_MAKE,
sstate checksums are fine and don't change as the number of cores do.
If you override it to a specific value, this does the cause the sstate
checksums to change. We don't want the checksums to change if the
value of this variable differs.
Therefore set a vardepvalue so a specific value is used for checksum
purposes.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
