pcmcia: remove AT91RM9200 Compact Flash driver

As noted by Arnd Bergmann, "we used to have three drivers for the same
hardware (pcmcia, pata and ide), and only the pcmcia driver remained
in the tree after drivers/ide/ was removed and pata_at91 did not get
converted to DT". "There is no dts file in tree that actually declares
either of them, so chances are that nobody is actually using the CF
slot on at91 any more."[1]

On this rationale, remove the AT91RM9200 Compact Flash driver, which
also assists in reaching "the goal of stopping exporting OF-specific
APIs of gpiolib".[2]

[1] https://lore.kernel.org/lkml/68c63077-848b-45f5-8aca-ed995391f2b6@www.fastmail.com/
[2] https://lore.kernel.org/lkml/Yy6d7TjqzUwGQnQa@penguin/Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/Kconfig

@@ -248,15 +248,6 @@ config OMAP_CF
 	  Say Y here to support the CompactFlash controller on OMAP.
 	  Note that this doesn't support "True IDE" mode.
 
-config AT91_CF
-	tristate "AT91 CompactFlash Controller"
-	depends on PCI
-	depends on OF
-	depends on PCMCIA && ARCH_AT91
-	help
-	  Say Y here to support the CompactFlash controller on AT91 chips.
-	  Or choose M to compile the driver as a module named "at91_cf".
-
 config ELECTRA_CF
 	tristate "Electra CompactFlash Controller"
 	depends on PCMCIA && PPC_PASEMI

drivers/pcmcia/Makefile

@@ -30,7 +30,6 @@ obj-$(CONFIG_PCMCIA_SA1100)			+= sa1100_cs.o
 obj-$(CONFIG_PCMCIA_SA1111)			+= sa1111_cs.o
 obj-$(CONFIG_PCMCIA_BCM63XX)			+= bcm63xx_pcmcia.o
 obj-$(CONFIG_OMAP_CF)				+= omap_cf.o
-obj-$(CONFIG_AT91_CF)				+= at91_cf.o
 obj-$(CONFIG_ELECTRA_CF)			+= electra_cf.o
 obj-$(CONFIG_PCMCIA_ALCHEMY_DEVBOARD)		+= db1xxx_ss.o
 obj-$(CONFIG_PCMCIA_MAX1600)			+= max1600.o