configs: Update Synopsys VDK for ARC HS38

configs: Update Synopsys VDK for ARC HS38

This updates Linux kernel for Synopsys ARC HS38 VDK so it matches real
platform and while at it bump kernel version to the latest.

Main changes:
 * Linux kernel v4.9.6 (latest in 4.9.x series in buildroot)
 * Add support of MMC controller which is used for rootfs
 * Add support of UIO which is used to communicate with EVSS

Now with this update image built by vanilla Buildroot VDK has
working UART, MMC, LCD, Ethernet, UIO etc.

And while at it we rename defconfing so it:
 1) Doesn't mention SMP any more - that's the only option anyways now
 2) Matches common naming scheme: vendor_arch_platform

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Zakharov Vlad <Vladislav.Zakharov@synopsys.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>