boot/at91bootstrap3: add BR2_TARGET_AT91BOOTSTRAP3_NEEDS_PYTHON3

Some at91bootstrap3 configurations now use Python scripts on the host
for NAND/PMEC related utilities. In order to be able to use those
scripts, this commit adds a new
BR2_TARGET_AT91BOOTSTRAP3_NEEDS_PYTHON3 which allows to express the
need for host-python3 as a dependency to build at91bootstrap3.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
[Thomas: this was extracted from a patch from Eugen adding
at91bootstrap 4.x support.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

boot/at91bootstrap3/Config.in

@@ -101,3 +101,11 @@ config BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_CONFIG_FILE
 	  Path to the at91bootstrap3 configuration file
 
 endif # BR2_TARGET_AT91BOOTSTRAP3
+
+config BR2_TARGET_AT91BOOTSTRAP3_NEEDS_PYTHON3
+	bool "needs host-python3"
+	help
+	  Enable this option if the at91bootstrap build process needs
+	  Python 3.x to be available on the host. This is needed in
+	  some at91bootstrap configurations to use NAND/PMECC Python
+	  scripts.

boot/at91bootstrap3/at91bootstrap3.mk

@@ -27,6 +27,10 @@ AT91BOOTSTRAP3_CPE_ID_PRODUCT = at91bootstrap
 AT91BOOTSTRAP3_INSTALL_IMAGES = YES
 AT91BOOTSTRAP3_INSTALL_TARGET = NO
 
+ifeq ($(BR2_TARGET_AT91BOOTSTRAP3_NEEDS_PYTHON3),y)
+AT91BOOTSTRAP3_DEPENDENCIES += host-python3
+endif
+
 AT91BOOTSTRAP3_CUSTOM_PATCH_DIR = \
 	$(call qstrip,$(BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_PATCH_DIR))