soc/intel: Drop dev parameter from soc_get_gen_io_dec_range()

This change drops the parameter `struct device *dev` from the function
`soc_get_gen_io_dec_range()`. This function uses the parameter dev to
get a pointer to config structure for extracting the decode ranges
configured by mainboard in device tree. However, there is no separate
chip driver for the LPC device which means that the SoC code can use
`config_of_soc()` to get to SoC chip config instead of using the LPC
device.

This change is being done in preparation to clean up the device
tree/chip config access in early stages that allows for optimizing
the inclusion of device tree elements in the early stages.

Change-Id: I3ea53ddc771f592dd0ea5e5e809be2d2eff7f16d
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49209
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

src/soc/intel/skylake/lpc.c

@@ -29,9 +29,9 @@ const struct lpc_mmio_range *soc_get_fixed_mmio_ranges(void)
 	return skl_lpc_fixed_mmio_ranges;
 }
 
-void soc_get_gen_io_dec_range(const struct device *dev, uint32_t *gen_io_dec)
+void soc_get_gen_io_dec_range(uint32_t *gen_io_dec)
 {
-	const config_t *config = config_of(dev);
+	const config_t *config = config_of_soc();
 
 	gen_io_dec[0] = config->gen1_dec;
 	gen_io_dec[1] = config->gen2_dec;