target: sunxi: enable kvm support

target: sunxi: enable kvm support

Unlike x86, kvm for arm has to be built into the kernel.  The kernel
config was prepared with the following command

    make kernel_menuconfig CONFIG_TARGET=platform

Then enable ARM_LPAE, VIRTUALIZATION, KVM in that order

Other config changes are done by the build system.  The following text
tries to explain some of them, for archive purposes probably...

 - BUILD_BIN2C.  It was dropped probably because the prompt is empty and
   no other config option selects it.  bin2c is a host executable for
   converting binary content to a piece of c code for inclusion
 - CRYPTO_DEV_SUN4I_SS.  It was dropped because the dependency CRYPTO_HW
   was not enabled.  Setting that aside, packaging it as a loadbable
   module in lieu of other sunxi specific modules seems more appropriate
 - PGTABLE_LEVELS.  It was changed from 2 to 3 because 3 is the default
   when ARM_LPAE is enabled
 - HAVE_KERNEL_GZIP, etc..  These are enabled in generic config
 - SCHED_INFO, ZLIB_INFLATE.  These were dropped probably for the same
   reason as for BUILD_BIN2C

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>