gdb/arm: Use type_align instead of arm_type_align

gdb/arm: Use type_align instead of arm_type_align

Replaces use of arm_type_align with common type_align function.

Doing this fixes a bug in arm_type_align where static fields are
considered as part of the alignment calculation of a struct, which
results in arguments passed on the stack being misaligned, this bug
was causing a failure in gdb.cp/many-args.exp.

Part of the old arm_type_align is retained and used as the gdbarch
type align callback in order to correctly align vectors.

gdb/ChangeLog:

	* arm-tdep.c (arm_type_align): Only handle vector override case.
	(arm_push_dummy_call): Use type_align.
	(arm_gdbarch_init): Register arm_type_align gdbarch function.