drisw: move build logic to build systems

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
diff --git a/Android.common.mk b/Android.common.mk
index 36d97c5..327f13f 100644
--- a/Android.common.mk
+++ b/Android.common.mk
@@ -98,6 +98,11 @@
 LOCAL_CFLAGS += -DHAVE_TIMESPEC_GET
 endif
 
+# Android's libc began supporting shm in Oreo
+ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 26 && echo true),true)
+LOCAL_CFLAGS += -DHAVE_SYS_SHM_H
+endif
+
 ifeq ($(strip $(MESA_ENABLE_ASM)),true)
 ifeq ($(TARGET_ARCH),x86)
 LOCAL_CFLAGS += \