linux-aspeed: ast2500: Always enable CONFIG_FB

DRM_FBDEV_EMULATION previously selected FB and was default y as long as DRM
was enabled. In commit f611b1e7624c ("drm: Avoid circular dependencies for
CONFIG_FB") the select was replaced with a depends on FB, disabling the
drivers that depended on it.

As the AST2500 uses the GFX device, and the uart-renderer process uses
fbterm to display to the FB device, we want CONFIG_FB=y for that system.

This is harmless for kernels that do not have the offending commit.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Change-Id: I57213b60f7fc06c89112a9825c7ed8ed7ff5e298
diff --git a/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g5/defconfig b/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g5/defconfig
index e7867a3..e194892 100644
--- a/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g5/defconfig
+++ b/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g5/defconfig
@@ -187,6 +187,7 @@
 CONFIG_VIDEO_ASPEED=y
 CONFIG_DRM=y
 CONFIG_DRM_ASPEED_GFX=y
+CONFIG_FB=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_ASPEED_VHUB=y
 CONFIG_USB_CONFIGFS=y