mips32: add fastdata loader working area

Add a working area that is preserved between calls to
mips_m4k_bulk_write_memory - this gives us a speed increase
of approx 3kb/sec during flash writes to the pic32mx.

This area is released during a resume/reset.

Signed-off-by: Spencer Oliver <ntfreak@users.sourceforge.net>

src/target/mips32.c

@@ -309,6 +309,7 @@ int mips32_init_arch_info(struct target *target, struct mips32_common *mips32, s
 {
 	target->arch_info = mips32;
 	mips32->common_magic = MIPS32_COMMON_MAGIC;
+	mips32->fast_data_area = NULL;
 
 	/* has breakpoint/watchpint unit been scanned */
 	mips32->bp_scanned = 0;