remove 2.6.30 support

target/linux/rdc/config-2.6.30

...inux/rdc/patches-2.6.30/001-rdc321x_mfd_southbridge.patch

target/linux/rdc/patches-2.6.30/002-rdc321x_gpio.patch

...rdc/patches-2.6.30/003-rdc321x_watchdog_southbridge.patch

...et/linux/rdc/patches-2.6.30/004-rdc321x_defs_remove.patch

target/linux/rdc/patches-2.6.30/006-yenta_mistery.patch

...inux/rdc/patches-2.6.30/009-rdc321x_select_embedded.patch

target/linux/rdc/patches-2.6.30/010-rdc_cpu_ident.patch

target/linux/rdc/patches-2.6.30/011-tune_lzma_options.patch

target/linux/rdc/patches-2.6.30/012-export_erase_write.patch

target/linux/rdc/patches-2.6.30/100-rdc_boards.patch

...t/linux/rdc/patches-2.6.30/110-rdc321x_watchdog_fix.patch

...nux/rdc/patches-2.6.30/120-panic_on_unrecovered_nmi.patch