games-emulation/azahar: add patch to use system oaknut

oaknut was package and the dependency was wired up in the ebuild, but a
patch to use the system installation was never actually added, leading
to a build failure on aarch64 due to the bundled copy being missing.

Signed-off-by: Violet Purcell <vimproved@inventati.org>

games-emulation/azahar/azahar-2123.1.ebuild

@@ -64,6 +64,7 @@ PATCHES=(
 	"${FILESDIR}/${PN}-2122.1-use-the-system-teakra-library.patch"
 	"${FILESDIR}/${PN}-2123-don-t-build-spirv-tools.patch"
 	"${FILESDIR}/${PN}-2123-use-the-zstd_seekable.h-header-from-externals.patch"
+	"${FILESDIR}/${PN}-2123.1-use-the-system-oaknut-library.patch"
 )
 
 # [directory]=license

games-emulation/azahar/files/azahar-2123.1-use-the-system-oaknut-library.patch

@@ -0,0 +1,13 @@
+Use the system's installation of oaknut.
+
+--- a/externals/CMakeLists.txt
++++ b/externals/CMakeLists.txt
+@@ -109,7 +109,7 @@ endif()
+ 
+ # Oaknut
+ if ("arm64" IN_LIST ARCHITECTURE)
+-    add_subdirectory(oaknut EXCLUDE_FROM_ALL)
++    add_library(oaknut INTERFACE)
+ endif()
+ 
+ # Dynarmic