build: drop ABI version from metadata

Preparation for supporting dynamic ABI versions that depend on the runtime
configuration. Read the suffix from the staging dir pkginfo version files.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

include/feeds.mk

@@ -43,5 +43,5 @@ endef
 
 # 1: package name
 define GetABISuffix
-$(if $(filter-out kmod-%,$(1)),$(if $(Package/$(1)/abiversion),$(if $(filter %0 %1 %2 %3 %4 %5 %6 %7 %8 %9,$(1)),-)$(Package/$(1)/abiversion)))
+$(if $(filter-out kmod-%,$(1)),$(foreach v,$(wildcard $(STAGING_DIR)/pkginfo/$(1).version),$(shell cat $(v))))
 endef