Added emulation of Commodore SL386SX-25 (PC Player II).

As part of this, added emulation of the onboard AVGA2, and fixed a couple of
bugs in the Cirrus Logic extended write modes.
Currently chipset (VLSI SCAMP) is missing EMS emulation.

src/Makefile.mingw-wx-sdl2

@@ -24,7 +24,7 @@ OBJ = 386.o 386_common.o 386_dynarec.o 386_dynarec_ops.o 808x.o 82091aa.o acc203
 	keyboard_olim24.o keyboard_pcjr.o keyboard_xt.o laserxt.o lpt.o lpt_dac.o lpt_dss.o mca.o mcr.o \
 	mem.o mem_bios.o mfm_at.o mfm_xebec.o model.o mouse.o mouse_msystems.o mouse_ps2.o mouse_serial.o \
 	mvp3.o neat.o nmi.o nvr.o nvr_tc8521.o olivetti_m24.o opti495.o paths.o pc.o pc87306.o pci.o pic.o \
-	piix.o pit.o ppi.o ps1.o ps2.o ps2_mca.o ps2_nvr.o pzx.o rom.o rtc.o rtc_tc8521.o scat.o scsi.o \
+	piix.o pit.o ppi.o ps1.o ps2.o ps2_mca.o ps2_nvr.o pzx.o rom.o rtc.o rtc_tc8521.o scamp.o scat.o scsi.o \
 	scsi_53c400.o scsi_aha1540.o scsi_cd.o scsi_hd.o scsi_zip.o serial.o sio.o sis496.o sl82c460.o \
 	sound.o sound_ad1848.o sound_adlib.o sound_adlibgold.o sound_audiopci.o sound_cms.o sound_dbopl.o \
 	sound_emu8k.o sound_gus.o sound_mpu401_uart.o sound_opl.o sound_pas16.o sound_ps1.o sound_pssj.o \