[ARM] 4391/1: make at91 debug unit support optional

The AT91x40 family doesn't have the debug unit like its bigger brothers.
But it does have the ID and extension registers (with the bit meanings
the same). Reorganize at91_dbgu.h to cater for this.

This also affects the load uncompressor, since it outputs to the
debug port.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/arch-at91/uncompress.h b/include/asm-arm/arch-at91/uncompress.h
index 30ac587..272a7e0 100644
--- a/include/asm-arm/arch-at91/uncompress.h
+++ b/include/asm-arm/arch-at91/uncompress.h
@@ -33,20 +33,24 @@
  */
 static void putc(int c)
 {
+#ifdef AT91_DBGU
 	void __iomem *sys = (void __iomem *) AT91_BASE_SYS;	/* physical address */
 
 	while (!(__raw_readl(sys + AT91_DBGU_SR) & AT91_DBGU_TXRDY))
 		barrier();
 	__raw_writel(c, sys + AT91_DBGU_THR);
+#endif
 }
 
 static inline void flush(void)
 {
+#ifdef AT91_DBGU
 	void __iomem *sys = (void __iomem *) AT91_BASE_SYS;	/* physical address */
 
 	/* wait for transmission to complete */
 	while (!(__raw_readl(sys + AT91_DBGU_SR) & AT91_DBGU_TXEMPTY))
 		barrier();
+#endif
 }
 
 #define arch_decomp_setup()