mbp_nvidia_bl: remove DMI dependency

This driver only has to deal with two different classes of hardware, but
right now it needs new DMI entries for every new machine. It turns out
that there's an ACPI device that uniquely identifies Apples with backlights,
so this patch reworks the driver into an ACPI one, identifies the hardware
by checking the PCI vendor of the root bridge and strips out all the DMI
code. It also changes the config text to clarify that it works on devices
other than Macbook Pros and GPUs other than nvidia.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Mourad De Clerck <mourad@aquazul.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/Kconfig

@@ -244,12 +244,12 @@ config BACKLIGHT_MAX8925
 	  If you have a LCD backlight connected to the WLED output of MAX8925
 	  WLED output, say Y here to enable this driver.
 
-config BACKLIGHT_MBP_NVIDIA
-       tristate "MacBook Pro Nvidia Backlight Driver"
+config BACKLIGHT_MACBOOK
+       tristate "MacBook Backlight Driver"
        depends on X86
        help
-         If you have an Apple Macbook Pro with Nvidia graphics hardware say Y
-	 to enable a driver for its backlight
+         If you have an Apple Macbook say Y to enable a driver for its
+	 backlight
 
 config BACKLIGHT_TOSA
 	tristate "Sharp SL-6000 Backlight Driver"

drivers/video/backlight/Makefile

@@ -27,7 +27,7 @@ obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o
 obj-$(CONFIG_BACKLIGHT_DA903X)	+= da903x_bl.o
 obj-$(CONFIG_BACKLIGHT_MAX8925)	+= max8925_bl.o
-obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
+obj-$(CONFIG_BACKLIGHT_MACBOOK)	+= mbp_nvidia_bl.o
 obj-$(CONFIG_BACKLIGHT_TOSA)	+= tosa_bl.o
 obj-$(CONFIG_BACKLIGHT_SAHARA)	+= kb3886_bl.o
 obj-$(CONFIG_BACKLIGHT_WM831X)	+= wm831x_bl.o