[MIPS] Alchemy: Fix Au1x SD controller IRQ

With the introduction of MIPS_CPU_IRQ_BASE, the hardcoded IRQ number of
the au1100/au1200 SD controller(s) is no longer valid.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

include/asm-mips/mach-au1x00/au1100_mmc.h

@@ -41,8 +41,11 @@
 
 #define NUM_AU1100_MMC_CONTROLLERS	2
 
-
-#define AU1100_SD_IRQ	2
+#if defined(CONFIG_SOC_AU1100)
+#define AU1100_SD_IRQ	AU1100_SD_INT
+#elif defined(CONFIG_SOC_AU1200)
+#define AU1100_SD_IRQ	AU1200_SD_INT
+#endif
 
 
 #define SD0_BASE	0xB0600000