linux-yocto/4.18: bug fixes and configuration tweaks

linux-yocto/4.18: bug fixes and configuration tweaks

Integrating the following commits:

  2ba9a28434f8 netfilter: use kvmalloc_array to allocate memory for hashtable
  6e1fae5d233a ipv4: net namespace does not inherit network configurations

As well as the following configuration changes:

  ed1978c99214 features/module-signing: add new feature
  a28fd4843381 edac: Drop CONFIG_EDAC_MM_EDAC and add dependency
  8ae63963256e xfs: add xfs support

(From OE-Core rev: d88ce948ff2c910e796b78be388bec9578f6eb9c)

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>