gdb: remove TYPE_ARRAY_BIT_STRIDE

gdb: remove TYPE_ARRAY_BIT_STRIDE

Remove it and update all callers to use the equivalent accessor methods.
A subsequent patch will make type::bit_stride work for array types
(effectively replacing this macro), but I wanted to keep this patch a
simple mechanical change.

gdb/ChangeLog:

	* gdbtypes.c (TYPE_ARRAY_BIT_STRIDE): Remove.  Update all
	callers to use the equivalent accessor methods.

Change-Id: I09e14bd45075f98567adce8a0b93edea7722f812