chromebook_samus: Enable the copy framebuffer

Update the video driver to support this feature and enable it on samus.
Also remove the multi-line scrolling since normal scrolling is fast enough
now.

With this change, the time taken to print the environment to the display
without CONFIG_CONSOLE_SCROLL_LINES is reduced from about 430ms to 12ms.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/chromebook_samus_defconfig b/configs/chromebook_samus_defconfig
index c18cba9..bf03cde 100644
--- a/configs/chromebook_samus_defconfig
+++ b/configs/chromebook_samus_defconfig
@@ -67,8 +67,8 @@
 CONFIG_TPM_TIS_LPC=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_KEYBOARD=y
+CONFIG_VIDEO_COPY=y
 CONFIG_FRAMEBUFFER_SET_VESA_MODE=y
 CONFIG_FRAMEBUFFER_VESA_MODE_11A=y
-CONFIG_CONSOLE_SCROLL_LINES=5
 CONFIG_TPM=y
 # CONFIG_GZIP is not set