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/include/asm/arch-mx7/clock.h b/arch/arm/include/asm/arch-mx7/clock.h
index 1d07fde..984bd3f 100644
--- a/arch/arm/include/asm/arch-mx7/clock.h
+++ b/arch/arm/include/asm/arch-mx7/clock.h
@@ -357,7 +357,7 @@
 void enable_ocotp_clk(unsigned char enable);
 #endif
 void enable_usboh3_clk(unsigned char enable);
-#ifdef CONFIG_SECURE_BOOT
+#ifdef CONFIG_IMX_HAB
 void hab_caam_clock_enable(unsigned char enable);
 #endif
 void mxs_set_lcdclk(uint32_t base_addr, uint32_t freq);