x86: Move FRAMEBUFFER_SET_VESA_MODE etc to video Kconfig

CONFIG_FRAMEBUFFER_SET_VESA_MODE and CONFIG_FRAMEBUFFER_VESA_MODE
are not x86-specific, so move them to drivers/video/Kconfig and
make them depend on VIDEO_VESA driver. Some cosmetic fixes are
applied to the Kconfig help text as well.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/minnowmax_defconfig b/configs/minnowmax_defconfig
index 87c99a8..744aca3 100644
--- a/configs/minnowmax_defconfig
+++ b/configs/minnowmax_defconfig
@@ -3,6 +3,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="minnowmax"
 CONFIG_TARGET_MINNOWMAX=y
 CONFIG_HAVE_INTEL_ME=y
+CONFIG_VIDEO_VESA=y
 CONFIG_FRAMEBUFFER_SET_VESA_MODE=y
 CONFIG_FRAMEBUFFER_VESA_MODE_11A=y
 CONFIG_SMP=y