Remove unnecessary defines/undefines in the makefiles

The following defines aren't referenced anywhere in the code base:
_LIB MULTICORE APPLY_CONCEALMENT THREAD_QUAD_CORE DISABLE_NEONINTR
ARMGCC

The DEFAULT_ARCH define isn't used within the encoder at all.

The ANDROID define isn't referenced anywhere either, and if necessary,
the automatically enabled define __ANDROID__ can be used instead.

The defines INSERT_LOGO and LOGO_EN were undefined in the makefiles,
but that is unnecessary since nothing actually defines them. The
decoder x86_64 makefile also undefined LOGO_EN; an architecture
specific makefile shouldn't touch such feature settings, otherwise
there's a risk that different builds for different architectures
behave significantly differently.

Change-Id: I13b86c8bf2feb3a381d904a13f18c3b35f40a575
diff --git a/decoder.arm64.mk b/decoder.arm64.mk
index 423c34d..5d92ed0 100644
--- a/decoder.arm64.mk
+++ b/decoder.arm64.mk
@@ -1,5 +1,5 @@
 libavcd_cflags_arm64 += -DARMV8
-libavcd_cflags_arm64 += -DDISABLE_NEONINTR  -DARM -DARMGCC
+libavcd_cflags_arm64 += -DARM
 
 libavcd_inc_dir_arm64   +=  $(LOCAL_PATH)/decoder/arm
 libavcd_inc_dir_arm64   +=  $(LOCAL_PATH)/common/armv8