imx: replace CONFIG_SECURE_BOOT with CONFIG_IMX_HAB

CONFIG_SECURE_BOOT is too generic and forbids to use it for cross
architecture purposes. If Secure Boot is required for imx, this means to
enable and use the HAB processor in the soc.

Signed-off-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3b0e315..c219a53 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -812,7 +812,7 @@
 	select ARCH_MISC_INIT
 	select BOARD_EARLY_INIT_F
 	select CPU_V7A
-	select SYS_FSL_HAS_SEC if SECURE_BOOT
+	select SYS_FSL_HAS_SEC if IMX_HAB
 	select SYS_FSL_SEC_COMPAT_4
 	select SYS_FSL_SEC_LE
 	imply MXC_GPIO
@@ -820,7 +820,7 @@
 config ARCH_MX6
 	bool "Freescale MX6"
 	select CPU_V7A
-	select SYS_FSL_HAS_SEC if SECURE_BOOT
+	select SYS_FSL_HAS_SEC if IMX_HAB
 	select SYS_FSL_SEC_COMPAT_4
 	select SYS_FSL_SEC_LE
 	select SYS_THUMB_BUILD if SPL