iOS, add arm64 support in libepub

Added patch to support arm64

Change-Id: If230ddd45b9d1fecc91e1cb529ff3f3da7f2c03d

external/libepubgen/UnpackedTarball_libepubgen.mk

@@ -18,6 +18,9 @@ epubgen_patches += libepubgen-validation3.patch.1
 epubgen_patches += libepubgen-vc.patch.1
 # Backport of <https://sourceforge.net/p/libepubgen/code/ci/2e9e9af9f49a78cca75d3c862c8dd4b5f7cc7eb2/> (and its deps).
 epubgen_patches += libepubgen-epub3.patch.1
+# iOS patch to support arm64
+epubgen_patches += libepubgen-ios.patch.1
+
 
 ifeq ($(COM_IS_CLANG),TRUE)
 ifneq ($(filter -fsanitize=%,$(CC)),)

external/libepubgen/libepubgen-ios.patch.1

+diff -Naur libepubgen/config.sub libepubgen.new/config.sub
+--- libepubgen/config.sub	2014-06-08 18:24:47.000000000 +0200
++++ libepubgen.new/config.sub	2017-09-04 21:41:46.000000000 +0200
+@@ -257,7 +257,7 @@
+ 	| alpha64 | alpha64ev[4-8] | alpha64ev56 | alpha64ev6[78] | alpha64pca5[67] \
+ 	| am33_2.0 \
+ 	| arc \
+-	| arm | arm[bl]e | arme[lb] | armv[2-8] | armv[3-8][lb] | armv7[arm] \
++	| arm | arm[bl]e | arme[lb] | armv[2-8] | armv[3-8][lb] | armv7[arm] | arm64 \
+ 	| avr | avr32 \
+ 	| be32 | be64 \
+ 	| bfin \
+@@ -370,7 +370,7 @@
+ 	| alpha-* | alphaev[4-8]-* | alphaev56-* | alphaev6[78]-* \
+ 	| alpha64-* | alpha64ev[4-8]-* | alpha64ev56-* | alpha64ev6[78]-* \
+ 	| alphapca5[67]-* | alpha64pca5[67]-* | arc-* \
+-	| arm-*  | armbe-* | armle-* | armeb-* | armv*-* \
++	| arm-*  | armbe-* | armle-* | armeb-* | armv*-* | arm64* \
+ 	| avr-* | avr32-* \
+ 	| be32-* | be64-* \
+ 	| bfin-* | bs2000-* \