clk: add si5351 i2c common clock driver

This patch adds a common clock driver for Silicon Labs Si5351a/b/c
i2c programmable clock generators. Currently, the driver does not
support VXCO feature of si5351b. Passing platform_data or DT bindings
selectively allows to overwrite stored Si5351 configuration which is
very helpful for clock generators with empty eeprom configuration.
Corresponding device tree binding documentation is also added.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
hsmmc: Fix problems with wifi module loading in v3.9 kernel.

Old u-boot set correctly pinmux and all other things to have correct
32kHz clock
provided for wifi module. When switching to new kernel all u-boot
specific init was
skipped. Pin dma_event_intr1 for CLKOUT2 is currently set in dts. This
wasn't enough to
have clock on CLKOUT2.

In cclock33xx_data is clk_32768_ck defined as root clock so don't
provide methods
for enable/disable. Use new specified clkout2_ck to have correct output
on CLOKOUT2 pin.

Signed-off-by: Marek Belisko <marek.belisko@streamunlimited.com>