xtensa: build kernel with text-section-literals

vmlinux.lds.S doesn't do anything special with literals, so instead of
keeping them separate put them into the corresponding text sections.
Drop explicit .literal sections from the vmlinux.lds.S, use standard
section macros. Mark literal pool locations in the assembly sources.
Unfortunately assembler doesn't put literals into .init sections and
external libgcc may still have .literal sections, so sed transformation
to the linker script is still needed.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
diff --git a/arch/xtensa/Makefile b/arch/xtensa/Makefile
index a206598..3a934b7 100644
--- a/arch/xtensa/Makefile
+++ b/arch/xtensa/Makefile
@@ -42,12 +42,12 @@
 
 # temporarily until string.h is fixed
 KBUILD_CFLAGS += -ffreestanding -D__linux__
-
-KBUILD_CFLAGS += -pipe -mlongcalls
-
+KBUILD_CFLAGS += -pipe -mlongcalls -mtext-section-literals
 KBUILD_CFLAGS += $(call cc-option,-mforce-no-pic,)
 KBUILD_CFLAGS += $(call cc-option,-mno-serialize-volatile,)
 
+KBUILD_AFLAGS += -mlongcalls -mtext-section-literals
+
 ifneq ($(CONFIG_LD_NO_RELAX),)
 LDFLAGS := --no-relax
 endif