reset: add driver for socfpga

Add a reset-controller driver for the socfpga platform.
The reset-controller has four banks with up to 32 entries all encapsulated in
one module block.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
---

Notes:
    Changes since v2:
        - remove superfluous ret in probe function
        - add Acked-by

    Changes since v1:
        - use BITS_PER_LONG everywhere instead of MAX_BANK_WIDTH
        - print pdev->dev.of_node->full_name on error
        - use proper IS_ERR/PTR_ERR

drivers/reset/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_RESET_CONTROLLER) += core.o
+obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_ARCH_STI) += sti/