mips_m4k and arm7_9 : Fix soft bkpt endianess for 16-bit instructions

The patch fix comparison of target data on the host by using
target_buffer_get_u16() to transform current_instr to
_host_ endianess before comparison.

src/target/arm7_9_common.c

@@ -392,6 +392,7 @@ static int arm7_9_unset_breakpoint(struct target *target, struct breakpoint *bre
 			{
 				return retval;
 			}
+			current_instr = target_buffer_get_u16(target, (uint8_t *)&current_instr);
 			if (current_instr == arm7_9->thumb_bkpt)
 				if ((retval = target_write_memory(target, breakpoint->address, 2, 1, breakpoint->orig_instr)) != ERROR_OK)
 				{

src/target/mips_m4k.c

@@ -643,7 +643,7 @@ static int mips_m4k_unset_breakpoint(struct target *target,
 			{
 				return retval;
 			}
-
+			current_instr = target_buffer_get_u16(target, (uint8_t *)&current_instr);
 			if (current_instr == MIPS16_SDBBP)
 			{
 				if ((retval = target_write_memory(target, breakpoint->address, 2, 1,