gdb: ARM: Fix for bugs in push and ldm instructions decoding

This patch corrects the register numbers and removes multiple loops in
recording procedure of instructions involving multiple registers.

gdb/ChangeLog:

2014-01-15  Omair Javaid  <omair.javaid@linaro.org>

	* arm-tdep.c (thumb_record_misc): Update to correct logical
	error while recording ldm, ldmia and pop instructions.