clk: lan966x: Fix linking error

clk: lan966x: Fix linking error

If the config options HAS_IOMEM is not set then the driver fails to link
with the following error:
clk-lan966x.c:(.text+0x950): undefined reference to
`devm_platform_ioremap_resource'

Therefor add missing dependencies: HAS_IOMEM and OF.

Fixes: b0f82ff7d189 ("clk: lan966x: Add lan966x SoC clock driver")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20220219141536.460812-1-horatiu.vultur@microchip.com
Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>