powerpc/ipic: Fix status get and status clear

IPIC Status is provided by register IPIC_SERSR and not by IPIC_SERMR
which is the mask register.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/sysdev/ipic.c

@@ -846,12 +846,12 @@ void ipic_disable_mcp(enum ipic_mcp_irq mcp_irq)
 
 u32 ipic_get_mcp_status(void)
 {
-	return ipic_read(primary_ipic->regs, IPIC_SERMR);
+	return ipic_read(primary_ipic->regs, IPIC_SERSR);
 }
 
 void ipic_clear_mcp_status(u32 mask)
 {
-	ipic_write(primary_ipic->regs, IPIC_SERMR, mask);
+	ipic_write(primary_ipic->regs, IPIC_SERSR, mask);
 }
 
 /* Return an interrupt vector or 0 if no interrupt is pending. */