mpc85xx: remove linux 3.10 support

target/linux/mpc85xx/config-3.10

...10/001-powerpc-85xx-add-gpio-keys-to-of-match-table.patch

target/linux/mpc85xx/patches-3.10/100-fix_mpc8568e_mds.patch

target/linux/mpc85xx/patches-3.10/110-fix_mpc8548_cds.patch

...c85xx/patches-3.10/120-mpc8548_cds_i8259_noirq_init.patch

...85xx/patches-3.10/130-mpc8548_cds_disable_i8259_irq.patch

...patches-3.10/140-powerpc-85xx-tl-wdr4900-v1-support.patch

target/linux/mpc85xx/patches-3.10/150-dts-p1010rdb-pa.patch

...inux/mpc85xx/patches-3.10/200-fix_gianfar_napi_poll.patch

...ches-3.10/210-spi-fsl-espi-preallocate-local-buffer.patch

...20-fix_gianfar_reported_number_of_sent_bytes_to_BQL.patch