defconfig: 8610: remove virtual frame buffer on perf defconfig

Virtual frame buffer is only used for early kernel bring-up before
display driver is ready.  This should be disabled once display
driver is available.

Change-Id: I61046ad4bafa7c3bc7d4009e18e35bcbd6a39e80
Signed-off-by: Xiaoming Zhou <zhoux@codeaurora.org>