[MIPS] XSS1500: Fix compilation

This patch fixes the compilation of the Au1000 XSS1500
board setup and irqmap code.

Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2 files changed