ioports: remove unused env parameter and compile only once

The CPU state parameter is not used, remove it and adjust callers. Now we
can compile ioport.c once for all targets.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/hw/isa_mmio.c b/hw/isa_mmio.c
index ec5da5f..ed0e189 100644
--- a/hw/isa_mmio.c
+++ b/hw/isa_mmio.c
@@ -28,7 +28,7 @@
 static void isa_mmio_writeb (void *opaque, target_phys_addr_t addr,
                                   uint32_t val)
 {
-    cpu_outb(NULL, addr & IOPORTS_MASK, val);
+    cpu_outb(addr & IOPORTS_MASK, val);
 }
 
 static void isa_mmio_writew (void *opaque, target_phys_addr_t addr,
@@ -37,7 +37,7 @@
 #ifdef TARGET_WORDS_BIGENDIAN
     val = bswap16(val);
 #endif
-    cpu_outw(NULL, addr & IOPORTS_MASK, val);
+    cpu_outw(addr & IOPORTS_MASK, val);
 }
 
 static void isa_mmio_writel (void *opaque, target_phys_addr_t addr,
@@ -46,14 +46,14 @@
 #ifdef TARGET_WORDS_BIGENDIAN
     val = bswap32(val);
 #endif
-    cpu_outl(NULL, addr & IOPORTS_MASK, val);
+    cpu_outl(addr & IOPORTS_MASK, val);
 }
 
 static uint32_t isa_mmio_readb (void *opaque, target_phys_addr_t addr)
 {
     uint32_t val;
 
-    val = cpu_inb(NULL, addr & IOPORTS_MASK);
+    val = cpu_inb(addr & IOPORTS_MASK);
     return val;
 }
 
@@ -61,7 +61,7 @@
 {
     uint32_t val;
 
-    val = cpu_inw(NULL, addr & IOPORTS_MASK);
+    val = cpu_inw(addr & IOPORTS_MASK);
 #ifdef TARGET_WORDS_BIGENDIAN
     val = bswap16(val);
 #endif
@@ -72,7 +72,7 @@
 {
     uint32_t val;
 
-    val = cpu_inl(NULL, addr & IOPORTS_MASK);
+    val = cpu_inl(addr & IOPORTS_MASK);
 #ifdef TARGET_WORDS_BIGENDIAN
     val = bswap32(val);
 #endif