cns3xxx: add experimental 3.18 support

target/linux/cns3xxx/config-3.18

...linux/cns3xxx/patches-3.18/000-cns3xxx_arch_include.patch

.../linux/cns3xxx/patches-3.18/001-cns3xxx_section_fix.patch

...atches-3.18/010-arm_introduce-dma-fiq-irq-broadcast.patch

target/linux/cns3xxx/patches-3.18/020-watchdog_support.patch

target/linux/cns3xxx/patches-3.18/025-smp_support.patch

target/linux/cns3xxx/patches-3.18/030-pcie_clock.patch

target/linux/cns3xxx/patches-3.18/031-pcie_init.patch

target/linux/cns3xxx/patches-3.18/040-fiq_support.patch

target/linux/cns3xxx/patches-3.18/045-twd_base.patch

target/linux/cns3xxx/patches-3.18/055-pcie_io.patch

target/linux/cns3xxx/patches-3.18/060-pcie_abort.patch

...t/linux/cns3xxx/patches-3.18/065-pcie_skip_inactive.patch

target/linux/cns3xxx/patches-3.18/070-i2c_support.patch

target/linux/cns3xxx/patches-3.18/075-spi_support.patch

target/linux/cns3xxx/patches-3.18/080-sata_support.patch

target/linux/cns3xxx/patches-3.18/085-ethernet_support.patch

target/linux/cns3xxx/patches-3.18/090-timers.patch

target/linux/cns3xxx/patches-3.18/095-gpio_support.patch

...linux/cns3xxx/patches-3.18/097-l2x0_cmdline_disable.patch