drm: mxsfb: Add i.MX7 and i.MX8M to the list of supported SoCs in Kconfig

Extend the Kconfig option description by listing the i.MX7 and i.MX8M
SoCs, as they are supported by the same driver. Replace the list of SoCs
in the short description with just "(e)LCDIF LCD controller" to avoid
expanding it further in the future as support for more SoCs is added.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200727020654.8231-17-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/mxsfb/Kconfig

@@ -5,7 +5,7 @@ config DRM_MXS
 	  Choose this option to select drivers for MXS FB devices
 
 config DRM_MXSFB
-	tristate "i.MX23/i.MX28/i.MX6SX MXSFB LCD controller"
+	tristate "i.MX (e)LCDIF LCD controller"
 	depends on DRM && OF
 	depends on COMMON_CLK
 	select DRM_MXS
@@ -15,7 +15,8 @@ config DRM_MXSFB
 	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	help
-	  Choose this option if you have an i.MX23/i.MX28/i.MX6SX MXSFB
-	  LCD controller.
+	  Choose this option if you have an LCDIF or eLCDIF LCD controller.
+	  Those devices are found in various i.MX SoC (including i.MX23,
+	  i.MX28, i.MX6SX, i.MX7 and i.MX8M).
 
 	  If M is selected the module will be called mxsfb.