staging: sm7xxfb: sm7xx becomes sm7xxfb

Rename sm7xx driver to sm7xxfb. Fix Kconfig and Makefile to fit the new
change.

Changes are coherent with the rest of stable framebuffer drivers. TODO
updated.

Signed-off-by: Javier M. Mellid <jmunhoz@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 05e33c7..38f1fb0 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -84,7 +84,7 @@
 
 source "drivers/staging/wlags49_h25/Kconfig"
 
-source "drivers/staging/sm7xx/Kconfig"
+source "drivers/staging/sm7xxfb/Kconfig"
 
 source "drivers/staging/crystalhd/Kconfig"