riscv --enable-targets=all on 32-bit host

[Alan Modra]

Attempting to build --enable-targets=all on a 32-bit host results in a
number of errors like the following.

eelf32lriscv.o: in function `gldelf32lriscv_after_allocation':
eelf32lriscv.c:98: undefined reference to `bfd_elf32_riscv_restart_relax_sections'

That's due to needing --enable-64-bit-bfd to get the riscv BFD support
built.

	* Makefile.am (ALL_EMULATION_SOURCES): Move riscv files to..
	(ALL_64_EMULATION_SOURCES): ..here.
	* Makefile.in: Regenerate.

diff --git a/ld/Makefile.am b/ld/Makefile.am
index 3fcaab71dc..606a9179b1 100644
--- a/ld/Makefile.am
+++ b/ld/Makefile.am
@@ -262,12 +262,6 @@ ALL_EMULATION_SOURCES = \
 	eelf32ppcsim.c \
 	eelf32ppcvxworks.c \
 	eelf32ppcwindiss.c \
-	eelf32lriscv.c \
-	eelf32lriscv_ilp32f.c \
-	eelf32lriscv_ilp32.c \
-	eelf32briscv.c \
-	eelf32briscv_ilp32f.c \
-	eelf32briscv_ilp32.c \
 	eelf32rl78.c \
 	eelf32rx.c \
 	eelf32rx_linux.c \
@@ -416,6 +410,12 @@ ALL_64_EMULATION_SOURCES = \
 	eelf32ltsmipn32.c \
 	eelf32ltsmipn32_fbsd.c \
 	eelf32mipswindiss.c \
+	eelf32lriscv.c \
+	eelf32lriscv_ilp32f.c \
+	eelf32lriscv_ilp32.c \
+	eelf32briscv.c \
+	eelf32briscv_ilp32f.c \
+	eelf32briscv_ilp32.c \
 	eelf64_aix.c \
 	eelf64bpf.c \
 	eelf64_ia64.c \

-- 
Alan Modra
Australia Development Lab, IBM