Merge changes I5ca7a004,Ibcb336a2 into integration

* changes:
  board/rdn1edge: use CREATE_SEQ helper macro to compare chip count
  build_macros: add create sequence helper function
diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index 1fa26cc..b6925d3 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -67,6 +67,17 @@
 $(if $(__numeric),$(error $(1) must be numeric))
 endef
 
+# CREATE_SEQ is a recursive function to create sequence of numbers from 1 to
+# $(2) and assign the sequence to $(1)
+define CREATE_SEQ
+$(if $(word $(2), $($(1))),\
+  $(eval $(1) += $(words $($(1))))\
+  $(eval $(1) := $(filter-out 0,$($(1)))),\
+  $(eval $(1) += $(words $($(1))))\
+  $(call CREATE_SEQ,$(1),$(2))\
+)
+endef
+
 # IMG_LINKERFILE defines the linker script corresponding to a BL stage
 #   $(1) = BL stage (2, 30, 31, 32, 33)
 define IMG_LINKERFILE
diff --git a/plat/arm/board/rdn1edge/platform.mk b/plat/arm/board/rdn1edge/platform.mk
index 99bb71d..135676d 100644
--- a/plat/arm/board/rdn1edge/platform.mk
+++ b/plat/arm/board/rdn1edge/platform.mk
@@ -51,8 +51,9 @@
 # Add the NT_FW_CONFIG to FIP and specify the same to certtool
 $(eval $(call TOOL_ADD_PAYLOAD,${NT_FW_CONFIG},--nt-fw-config))
 
-ifneq ($(CSS_SGI_CHIP_COUNT),$(filter $(CSS_SGI_CHIP_COUNT),1 2))
- $(error  "Chip count for RDN1Edge platform should either 1 or 2, currently \
+$(eval $(call CREATE_SEQ,SEQ,2))
+ifneq ($(CSS_SGI_CHIP_COUNT),$(filter $(CSS_SGI_CHIP_COUNT),$(SEQ)))
+ $(error  "Chip count for RDN1Edge platform should be one of $(SEQ), currently \
    set to ${CSS_SGI_CHIP_COUNT}.")
 endif