ARM: only use one set of dummy FPA registers

All ARM cores need to provide obsolete FPA registers in their
GDB register dumps.  (Even though cores with floating point
support now generally use some version of VFP...)

Clean up that support a bit by sharing the same dummy registers,
and removing the duplicate copies.  Eventually we shouldn't need
to export those dummies.

(This makes the ARMv7-M support include the armv4_5 header, and
cleans up related #includes, but doesn't yet use anything from
there except those dummies.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

src/target/cortex_m3.c

@@ -334,6 +334,9 @@ static int cortex_m3_debug_entry(struct target *target)
 	xPSR = buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_xPSR].value, 0, 32);
 
 #ifdef ARMV7_GDB_HACKS
+	/* FIXME this breaks on scan chains with more than one Cortex-M3.
+	 * Instead, each CM3 should have its own dummy value...
+	 */
 	/* copy real xpsr reg for gdb, setting thumb bit */
 	buf_set_u32(armv7m_gdb_dummy_cpsr_value, 0, 32, xPSR);
 	buf_set_u32(armv7m_gdb_dummy_cpsr_value, 5, 1, 1);