include/exec: Move vaddr defines to separate file

include/exec: Move vaddr defines to separate file

Needed to work around circular includes. vaddr is currently defined in
cpu-common.h and needed by hw/core/cpu.h, but cpu-common.h also need
cpu.h to know the size of the CPUState.

[Maybe we can instead move parts of cpu-common.h w. hw/core/cpu.h to
sort out the circular inclusion.]

Signed-off-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20240119144024.14289-7-anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[rth: Add include of vaddr.h into cpu-common.h]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>