target-m68k: Return M68kCPU from cpu_m68k_init()

Turn cpu_init() into a static inline function for backwards
compatibility.

Signed-off-by: Andreas Färber <afaerber@suse.de>
mcf5206: Pass M68kCPU to mcf5206_init()

Store it in m5206_mbar_state. Prepares for passing M68kCPU to
m68k_set_irq_level().

Signed-off-by: Andreas Färber <afaerber@suse.de>
mcf_intc: Pass M68kCPU to mcf_intc_init()

Store it in mcf_intc_state.
Prepares for passing it to m68k_set_irq_level().

Signed-off-by: Andreas Färber <afaerber@suse.de>
target-m68k: Pass M68kCPU to m68k_set_irq_level()

Simplifies use of cpu_reset_interrupt() et al.

Signed-off-by: Andreas Färber <afaerber@suse.de>