atom-pc: Prefer linux-yocto_3.4

Atom-pc missed the kernel refresh last time around. 3.0 is on its way
out. Set the PREFERRED_PROVIDER to 3.4.

Boot tested on a Toshiba NB-305 using core-image-minimal.

(From meta-yocto rev: 5457e02d896f62d8b2e94be071083770a97dd38b)

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-yocto-bsp/conf/machine/atom-pc.conf

@@ -10,7 +10,7 @@ MACHINE_FEATURES = "screen keyboard pci usbhost ext2 ext3 x86 wifi acpi alsa"
 KERNEL_IMAGETYPE = "bzImage"
 
 PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto"
-PREFERRED_VERSION_linux-yocto ?= "3.0%"
+PREFERRED_VERSION_linux-yocto ?= "3.4%"
 PREFERRED_PROVIDER_virtual/xserver ?= "xserver-xorg"
 XSERVER ?= "xserver-xorg \
            xserver-xorg-extension-glx \