MIPS: Malta: Remove ttyS2 serial for CMP platforms

MIPS: Malta: Remove ttyS2 serial for CMP platforms

Commit 1893554c0145573315fac913075bce7636a88b25
"MIPS: Malta: Fix interupt number of CBUS UART"

fixed the IRQ number for the ttyS2 CBUS UART. However, this now
conflicts with the GIC IPI1 interrupt in CMP platforms. The Malta
interrupt code arbitrarily binds IPIs to INT2 and INT3 and since
ttyS2 uses the INT2 IRQ line, closing the device disables the
INT2 interrupt and this effectively disables the IPI1 interrupt
as well. This patch is mainly a workaround until the Malta code
is fixed properly.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6045/