ARM: rpi: rename rpi_b to rpi

The U-Boot port runs on a variety of RPi models, not just the B. So,
rename the port to something slightly more generic.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0982117..7a64b66 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -396,8 +396,8 @@
 	bool "Support mx35pdk"
 	select CPU_ARM1136
 
-config TARGET_RPI_B
-	bool "Support rpi_b"
+config TARGET_RPI
+	bool "Support rpi"
 	select CPU_ARM1176
 
 config TARGET_TNETV107X_EVM
@@ -931,7 +931,7 @@
 source "board/phytec/pcm051/Kconfig"
 source "board/ppcag/bg0900/Kconfig"
 source "board/pxa255_idp/Kconfig"
-source "board/raspberrypi/rpi_b/Kconfig"
+source "board/raspberrypi/rpi/Kconfig"
 source "board/ronetix/pm9261/Kconfig"
 source "board/ronetix/pm9263/Kconfig"
 source "board/ronetix/pm9g45/Kconfig"