Minor change to Makfile target 'clean' to catch missed file.

Updated host/tools_support.c for new get_user_pages() function.

At some point the function prototype changed from this:

    long get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                unsigned long start, unsigned long nr_pages,
                int write, int force, struct page **pages,
                struct vm_area_struct **vmas);

into this:

    long get_user_pages(unsigned long start, unsigned long nr_pages,
                    unsigned int gup_flags, struct page **pages,
                    struct vm_area_struct **vmas);

With the individual 'write' and 'force' flags transforming into gup_flags per
this patch:

    https://patchwork.kernel.org/project/linux-arm-kernel/patch/20161013002020.3062-7-lstoakes@gmail.com/

Updated host/tools_support.c, changing from page_cache_release() to put_page().

See also:

  - https://github.com/torvalds/linux/commit/1fa64f198b9f8d6ec0f7aec7c18dc94684391140

  - https://github.com/torvalds/linux/commit/09cbfeaf1a5a67bfb3201e0c83c810cecb2efa5a

Fixed misleading indentation in host/pm_pcstate.c

Added a basic README to the project.

Updated host/linvnet.c per the changes to net_device->destructor.

See also:

  - https://github.com/torvalds/linux/commit/cf124db566e6b036b8bcbe8decbed740bdfac8c6

Updated host/linvcons.c to use new timer API introduced in Linux 4.14.0.

See also:

  - https://lwn.net/Articles/735887/

  - https://stackoverflow.com/questions/53839625

A few cosmetic changes found while making the previous commit.

Replaced deprecated pci_enable_msix() call with equivalent pci_enable_msix_exact() call.

See also:

  - https://patchwork.kernel.org/project/linux-pci/patch/1412955343-27239-1-git-send-email-agordeev@redhat.com/

  - http://tomoyo.osdn.jp/cgi-bin/lxr/source/Documentation/PCI/MSI-HOWTO.txt?v=linux-4.7.10

Manually building a 'clean' target in the Makefile.
After completing the port to the newer kernel, the pattern behind this cleanup
can be better organized.

Manually specified target architecture in Makefile.

Initial commit of files contained in `mpss-modules-3.8.6.tar.bz2` for Intel Xeon Phi.