memory: squash drivers/memory/Makefile.asm-offsets

drivers/memory/Makefile.asm-offsets is small enough, and included
from a single place.

Squash it into drivers/memory/Makefile.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 90161de..91ae4eb 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -28,6 +28,9 @@
 
 AFLAGS_ti-emif-sram-pm.o	:=-Wa,-march=armv7-a
 
-include drivers/memory/Makefile.asm-offsets
-
 drivers/memory/ti-emif-sram-pm.o: include/generated/ti-emif-asm-offsets.h
+
+include/generated/ti-emif-asm-offsets.h: drivers/memory/emif-asm-offsets.s FORCE
+	$(call filechk,offsets,__TI_EMIF_ASM_OFFSETS_H__)
+
+targets += emif-asm-offsets.s