rpi: remove redundant board files

Now that rpi_*defconfig and Kconfig (rather than the config header file)
provide the identity of the build, we don't need to separate config
headers and board directories for each RPi variant. Set CONFIG_SYS_BOARD
and CONFIG_SYS_CONFIG_NAME so that we can get rid of the duplication. This
requires a tiny number of extra ifdefs in the config header.

The only disadvantage of this approach is that the $board/$board_name
environment variables aren't as descriptive as they used to be. This isn't
really an issue because those only exist to allow scripts to create DTB
filenames at runtime. However, the RPi board code already sets $fdtfile to
something more accurate based on FW-reported board ID anyway.

While at it, unify some Kconfig select options, and add a MAINTAINERS
entry for bcm283x too.

Partially-suggested-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-bcm283x/Kconfig b/arch/arm/mach-bcm283x/Kconfig
index f4c9502..69f7a46 100644
--- a/arch/arm/mach-bcm283x/Kconfig
+++ b/arch/arm/mach-bcm283x/Kconfig
@@ -1,14 +1,30 @@
 config BCM2835
 	bool "Broadcom BCM2835 SoC support"
 	depends on ARCH_BCM283X
+	select CPU_ARM1176
 
 config BCM2836
 	bool "Broadcom BCM2836 SoC support"
 	depends on ARCH_BCM283X
+	select ARMV7_LPAE
+	select CPU_V7
 
 config BCM2837
 	bool "Broadcom BCM2837 SoC support"
 	depends on ARCH_BCM283X
+
+config BCM2837_32B
+	bool "Broadcom BCM2837 SoC 32-bit support"
+	depends on ARCH_BCM283X
+	select BCM2837
+	select ARMV7_LPAE
+	select CPU_V7
+
+config BCM2837_64B
+	bool "Broadcom BCM2837 SoC 64-bit support"
+	depends on ARCH_BCM283X
+	select BCM2837
+	select ARM64
 
 menu "Broadcom BCM283X family"
 	depends on ARCH_BCM283X
@@ -27,7 +43,6 @@
 
 	  This option creates a build targetting the ARM1176 ISA.
 	select BCM2835
-	select CPU_ARM1176
 
 config TARGET_RPI_2
 	bool "Raspberry Pi 2"
@@ -50,9 +65,7 @@
 	  https://github.com/raspberrypi/firmware/issues/572".
 
 	  This option creates a build targetting the ARMv7/AArch32 ISA.
-	select ARMV7_LPAE
 	select BCM2836
-	select CPU_V7
 
 config TARGET_RPI_3_32B
 	bool "Raspberry Pi 3 32-bit build"
@@ -68,9 +81,7 @@
 	  about the HDMI/usbkbd console.
 
 	  This option creates a build targetting the ARMv7/AArch32 ISA.
-	select ARMV7_LPAE
-	select BCM2837
-	select CPU_V7
+	select BCM2837_32B
 
 config TARGET_RPI_3
 	bool "Raspberry Pi 3 64-bit build"
@@ -98,16 +109,12 @@
 	  https://github.com/raspberrypi/firmware/issues/579.
 
 	  This option creates a build targetting the ARMv8/AArch64 ISA.
-	select ARM64
-	select BCM2837
+	select BCM2837_64B
 
 endchoice
 
 config SYS_BOARD
-	default "rpi" if TARGET_RPI
-	default "rpi_2" if TARGET_RPI_2
-	default "rpi_3_32b" if TARGET_RPI_3_32B
-	default "rpi_3" if TARGET_RPI_3
+	default "rpi"
 
 config SYS_VENDOR
 	default "raspberrypi"
@@ -116,9 +123,6 @@
 	default "bcm283x"
 
 config SYS_CONFIG_NAME
-	default "rpi" if TARGET_RPI
-	default "rpi_2" if TARGET_RPI_2
-	default "rpi_3_32b" if TARGET_RPI_3_32B
-	default "rpi_3" if TARGET_RPI_3
+	default "rpi"
 
 endmenu