Fix emu on mipsel.

* conf/Makefile.common (CFLAGS_PLATFORM): Add -mflush-func
	=grub_cpu_flush_cache on all mips and not only yeeloong.
	* configure.ac (COND_mips): New conditional.
	* grub-core/Makefile.am (KERNEL_HEADER_FILES): Add libgcc on all
	platforms.
	* grub-core/kern/emu/cache.S (__mips__): Use _flush_cache.
	* grub-core/kern/emu/full.c (grub_arch_dl_init_linker)
	[GRUB_LINKER_HAVE_INIT]: New function.
	(grub_emu_post_init): Likewise.
	* grub-core/kern/emu/lite.c (grub_emu_post_init): Likewise.
	* grub-core/kern/emu/main.c: Use grub_emu_post_init.
	* include/grub/cache.h (_mips): Include mips/cache.h.
	* include/grub/disk.h [GRUB_UTIL || GRUB_MACHINE_EMU]: Add missing
	LVM and RAID prototypes.
	* include/grub/emu/misc.h (grub_emu_post_init): New proto.
	* include/grub/mips/time.h (grub_cpu_idle) [GRUB_MACHINE_EMU]: New
	function.

include/grub/mips/time.h

@@ -0,0 +1,6 @@
+#ifdef GRUB_MACHINE_EMU
+static inline void
+grub_cpu_idle(void)
+{
+}
+#endif