Convert CONFIG_USB_EHCI_IS_TDI to Kconfig

On mvebu this is defined if and only if !ARM64.

Otherwise it is defined for boards with ARCH_MX23, ARCH_TEGRA and
ARCH_ZYNQ, and also for SOC_AR934X (tplink_wdr4300).

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
diff --git a/arch/arm/mach-kirkwood/include/mach/config.h b/arch/arm/mach-kirkwood/include/mach/config.h
index f262d70..cf6b1b9 100644
--- a/arch/arm/mach-kirkwood/include/mach/config.h
+++ b/arch/arm/mach-kirkwood/include/mach/config.h
@@ -63,13 +63,6 @@
 #endif /* CONFIG_CMD_NET */
 
 /*
- * USB/EHCI
- */
-#ifdef CONFIG_CMD_USB
-#define CONFIG_USB_EHCI_IS_TDI
-#endif /* CONFIG_CMD_USB */
-
-/*
  * IDE Support on SATA ports
  */
 #ifdef CONFIG_IDE
diff --git a/arch/mips/mach-ath79/Kconfig b/arch/mips/mach-ath79/Kconfig
index bdb23b5..cd85d1b 100644
--- a/arch/mips/mach-ath79/Kconfig
+++ b/arch/mips/mach-ath79/Kconfig
@@ -20,6 +20,7 @@
 	select SUPPORTS_BIG_ENDIAN
 	select SUPPORTS_CPU_MIPS32_R1
 	select SUPPORTS_CPU_MIPS32_R2
+	select USB_EHCI_IS_TDI if USB_EHCI_HCD
 	help
 	  This supports QCA/Atheros ar934x family SOCs.