Over a dozen new ARM System-on-a-Chips are new to the mainline Linux 4.6 kernel code. The newly-supported platforms include Axis Artpec-6 SoC (artpec6), TI keystone-k2g, Mediatek MT7623 (mt7623), Allwinner A83T SoC (a83t), NXP i.MX6QP SoC (imx6qp), ST Microelectronics stm32f469, Annapurna Labs Alpine (alpine-v2), Marvell Armada 3700 SoCs (armada-37xx), Marvell Armada 7000/8000 SoCs (armada-7xxx/8xxx), Amlogic S905 (meson-gxbb), Qualcomm Snapdragon 820 (msm8996), Socionext UniPhier (uniphier-ph1), ARM Juno Development Platform (juno-r2), Allwinner A64 SoC, and Broadcom Vulcan (vulcan).
There is also new board/machine support for the Buffalo Linkstation LS-QVL/LS-GL, Cubietruck Plus, D-Link DIR-885L, Google's Nexus 7, Homlet v2, Lamono R1, Itead Ibox, LG Optimus Black, and the Raspberry Pi Model A.
Other highlights include Rockchip RK3368 power domain support, DeviceTree support for the AMD Opteron ARM powered 96Boards HuskyBoard and AMD Overdrive, SMP support for the Mediatek MT7623 and MT2701 SoCs, improved support for the Nokia N900, Broadcom BCM2835 Raspberry Pi improvements, and many other ARM SoC/platform changes.
More details on the ARM SoC improvements and additions for Linux 4.6 can be found via this LKML mailing list series.