[MIPSR6] Skip pixelflinger, memset assembler code on mips32r6

Temporarily use generic C-coded libpixelflinger & memset on mips32r6.

Change-Id: I629b11ba955eaba323cba1df96c39f75f4d24d62
diff --git a/libpixelflinger/Android.mk b/libpixelflinger/Android.mk
index 484cf50..6a3a58f 100644
--- a/libpixelflinger/Android.mk
+++ b/libpixelflinger/Android.mk
@@ -44,11 +44,13 @@
 	arch-arm64/col32cb16blend.S \
 	arch-arm64/t32cb16blend.S \
 
+ifndef ARCH_MIPS_REV6
 PIXELFLINGER_SRC_FILES_mips := \
 	codeflinger/MIPSAssembler.cpp \
 	codeflinger/mips_disassem.c \
 	arch-mips/t32cb16blend.S \
 
+endif
 #
 # Shared library
 #