boot-wrapper-aarch64: Allow users to select the PSCI SMP boot method

Signed-off-by: Hollis Blanchard <hollis_blanchard@mentor.com>
[Thomas:
 - remove "default n"
 - pass explicit --disable-psci]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

boot/boot-wrapper-aarch64/Config.in

@@ -32,4 +32,10 @@ config BR2_TARGET_BOOT_WRAPPER_AARCH64_BOOTARGS
 	  Kernel bootargs to embed inside the image generated by the
 	  boot wrapper.
 
+config BR2_TARGET_BOOT_WRAPPER_AARCH64_PSCI
+	bool "Boot secondary SMP cores using PSCI"
+	help
+	  Boot secondary SMP cores using PSCI firmware calls. If
+	  disabled, the spin-table method is used instead.
+
 endif

boot/boot-wrapper-aarch64/boot-wrapper-aarch64.mk

@@ -30,6 +30,12 @@ BOOT_WRAPPER_AARCH64_CONF_OPTS = \
 	--with-kernel-dir=$(LINUX_DIR) \
 	--with-cmdline=$(BR2_TARGET_BOOT_WRAPPER_AARCH64_BOOTARGS)
 
+ifeq ($(BR2_TARGET_BOOT_WRAPPER_AARCH64_PSCI),y)
+BOOT_WRAPPER_AARCH64_CONF_OPTS += --enable-psci
+else
+BOOT_WRAPPER_AARCH64_CONF_OPTS += --disable-psci
+endif
+
 # We need to convince the configure script that the Linux kernel tree
 # exists, as well as the DTB and the kernel Image. Even though those
 # are available on the build machine, the configure script uses