exec: Make cpu_memory_rw_debug() target agnostic

cpu_memory_rw_debug() is declared in "exec/cpu-all.h" which
contains target-specific declarations. To be able to use it
from target agnostic source, move the declaration to the
generic "exec/cpu-common.h" header.

Replace the target-specific 'target_ulong' type by 'vaddr'
which better reflects the argument type, and is target agnostic.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-5-f4bug@amsat.org>