[PATCH V2] MIPS: Alchemy: fix build with SERIAL_8250=n

[Manuel Lauss <manuel.lauss@googlemail.com>]

In commit 7d172bfe ("Alchemy: Add UART PM methods") I introduced
platform PM methods which call a function of the 8250 driver;
this patch works around link failures when the kernel is built
without 8250 support.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
---
V2: added commit name to patch description as per Sergei's suggestion.

 arch/mips/alchemy/common/platform.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/mips/alchemy/common/platform.c 
b/arch/mips/alchemy/common/platform.c
index 3691630..9e7814d 100644
--- a/arch/mips/alchemy/common/platform.c
+++ b/arch/mips/alchemy/common/platform.c
@@ -27,6 +27,7 @@
 static void alchemy_8250_pm(struct uart_port *port, unsigned int state,
                            unsigned int old_state)
 {
+#ifdef CONFIG_SERIAL_8250
        switch (state) {
        case 0:
                if ((__raw_readl(port->membase + UART_MOD_CNTRL) & 3) != 3) {
@@ -49,6 +50,7 @@ static void alchemy_8250_pm(struct uart_port *port, unsigned 
int state,
                serial8250_do_pm(port, state, old_state);
                break;
        }
+#endif
 }
 
 #define PORT(_base, _irq)                                      \
-- 
1.7.3.2