aspeed/smc: Rename AspeedSMCFlash 'id' to 'cs'

'cs' is a more appropriate name to index SPI flash devices.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

include/hw/ssi/aspeed_smc.h

@@ -33,7 +33,7 @@ struct AspeedSMCState;
 typedef struct AspeedSMCFlash {
     struct AspeedSMCState *controller;
 
-    uint8_t id;
+    uint8_t cs;
 
     MemoryRegion mmio;
 } AspeedSMCFlash;