xtensa: rename BUILTIN_DTB to BUILTIN_DTB_SOURCE

When building some xtensa config, I hit the following warning:
  drivers/staging/mt7621-dts/Kconfig:4:warning: 'BUILTIN_DTB' has wrong type.
  'select' only accept arguments of bool and tristate type

It is due to some arch use BUILTIN_DTB as a flag for the need to builtin
dtb but xtensa use it as a string for which dtb to bulltin.
But for this (which dtb to build), it is better to use
BUILTIN_DTB_SOURCE like other arch do.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/Kconfig

@@ -451,7 +451,7 @@ config USE_OF
 	help
 	  Include support for flattened device tree machine descriptions.
 
-config BUILTIN_DTB
+config BUILTIN_DTB_SOURCE
 	string "DTB to build into the kernel image"
 	depends on OF
 

arch/xtensa/boot/dts/Makefile

@@ -7,9 +7,9 @@
 #
 #
 
-BUILTIN_DTB := $(patsubst "%",%,$(CONFIG_BUILTIN_DTB)).dtb.o
-ifneq ($(CONFIG_BUILTIN_DTB),"")
-obj-$(CONFIG_OF) += $(BUILTIN_DTB)
+BUILTIN_DTB_SOURCE := $(patsubst "%",%,$(CONFIG_BUILTIN_DTB_SOURCE)).dtb.o
+ifneq ($(CONFIG_BUILTIN_DTB_SOURCE),"")
+obj-$(CONFIG_OF) += $(BUILTIN_DTB_SOURCE)
 endif
 
 # for CONFIG_OF_ALL_DTBS test

arch/xtensa/configs/audio_kc705_defconfig

@@ -34,7 +34,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0xfd050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=0x38000000@0"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="kc705"
+CONFIG_BUILTIN_DTB_SOURCE="kc705"
 # CONFIG_COMPACTION is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_PM=y

arch/xtensa/configs/cadence_csp_defconfig

@@ -38,7 +38,7 @@ CONFIG_HIGHMEM=y
 # CONFIG_PCI is not set
 CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="csp"
+CONFIG_BUILTIN_DTB_SOURCE="csp"
 # CONFIG_COMPACTION is not set
 CONFIG_XTFPGA_LCD=y
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set

arch/xtensa/configs/generic_kc705_defconfig

@@ -33,7 +33,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0xfd050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=0x38000000@0"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="kc705"
+CONFIG_BUILTIN_DTB_SOURCE="kc705"
 # CONFIG_COMPACTION is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_NET=y

arch/xtensa/configs/nommu_kc705_defconfig

@@ -39,7 +39,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0x9d050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=256M@0x60000000"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="kc705_nommu"
+CONFIG_BUILTIN_DTB_SOURCE="kc705_nommu"
 CONFIG_BINFMT_FLAT=y
 CONFIG_NET=y
 CONFIG_PACKET=y

arch/xtensa/configs/smp_lx200_defconfig

@@ -38,7 +38,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0xfd050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=96M@0"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="lx200mx"
+CONFIG_BUILTIN_DTB_SOURCE="lx200mx"
 # CONFIG_COMPACTION is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_NET=y