Rename *_partition_map to part_*

	* partmap/acorn.c (grub_acorn_partition_map): Set name to 'part_acorn'.
	* partmap/amiga.c (grub_amiga_partition_map): Set name to 'part_amiga'.
	* partmap/apple.c (grub_apple_partition_map): Set name to 'part_apple'.
	* partmap/gpt.c (grub_gpt_partition_map): Set name to 'part_gpt'.
	All users updated.
	* partmap/msdos.c (grub_msdos_partition_map): Set name to 'part_msdos'.
	All users updated.
	* partmap/sun.c (grub_sun_partition_map): Set name to 'part_sun'.
	* util/grub-probe.c (probe_partmap): Don't transform partition name
	to get module name.