video: fix up versatile CLCD helper move

commit 11c32d7b6274cb0f ("video: move Versatile CLCD helpers")
moved files out of the plat-versatile directory but in the process
got a few of the dependencies wrong:

- If CONFIG_FB is not set, the file no longer gets built, resulting
in a link error
- If CONFIG_FB or CONFIG_FB_ARMCLCD are disabled, we also get a
Kconfig warning for incorrect dependencies due to the symbol
being 'select'ed from the platform Kconfig.
- When the file is not built, we also get a link error for missing
symbols.

This patch should fix all three, by removing the 'select' statements,
changing the Kconfig description of the symbol to be enabled in
exactly the right configurations, and adding inline stub functions
for the case when the framebuffer driver is disabled.

Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>

arch/arm/Kconfig

···
 	select ICST
 	select NEED_MACH_MEMORY_H
 	select PLAT_VERSATILE
-	select PLAT_VERSATILE_CLCD
 	help
 	  This enables support for ARM Ltd RealView boards.
 
···
 	select HAVE_MACH_CLKDEV
 	select ICST
 	select PLAT_VERSATILE
-	select PLAT_VERSATILE_CLCD
 	select PLAT_VERSATILE_CLOCK
 	select VERSATILE_FPGA_IRQ
 	help

arch/arm/mach-vexpress/Kconfig

···
 	select ICST
 	select NO_IOPORT_MAP
 	select PLAT_VERSATILE
-	select PLAT_VERSATILE_CLCD
 	select POWER_RESET
 	select POWER_RESET_VEXPRESS
 	select POWER_SUPPLY

drivers/video/fbdev/Kconfig

···
 
 # Helper logic selected only by the ARM Versatile platform family.
 config PLAT_VERSATILE_CLCD
-	depends on FB_ARMCLCD
-	depends on (PLAT_VERSATILE || ARCH_INTEGRATOR)
-	default y
-	bool
+	def_bool ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS
+	depends on FB_ARMCLCD && FB=y
 
 config FB_ACORN
 	bool "Acorn VIDC support"

include/linux/platform_data/video-clcd-versatile.h

···
 #ifndef PLAT_CLCD_H
 #define PLAT_CLCD_H
 
+#ifdef CONFIG_PLAT_VERSATILE_CLCD
 struct clcd_panel *versatile_clcd_get_panel(const char *);
 int versatile_clcd_setup_dma(struct clcd_fb *, unsigned long);
 int versatile_clcd_mmap_dma(struct clcd_fb *, struct vm_area_struct *);
 void versatile_clcd_remove_dma(struct clcd_fb *);
+#else
+static inline struct clcd_panel *versatile_clcd_get_panel(const char *s)
+{
+	return NULL;
+}
+static inline int versatile_clcd_setup_dma(struct clcd_fb *fb, unsigned long framesize)
+{
+	return -ENODEV;
+}
+static inline int versatile_clcd_mmap_dma(struct clcd_fb *fb, struct vm_area_struct *vm)
+{
+	return -ENODEV;
+}
+static inline void versatile_clcd_remove_dma(struct clcd_fb *fb)
+{
+}
+#endif
 
 #endif