soc/intel/apollolake: Clean up code by using common FAST_SPI module

This patch currently contains the following -
 1. Use SOC_INTEL_COMMON_BLOCK_FAST_SPI kconfig for common FAST_SPI code.
 2. Perform FAST_SPI programming by calling APIs from common FAST_SPI library.
 3. Use common FAST_SPI header file.

Change-Id: Ifd72734dadda541fe4c828e4f1716e532ec69c27
Signed-off-by: Barnali Sarkar <barnali.sarkar@intel.com>
Reviewed-on: https://review.coreboot.org/19080
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/apollolake/Kconfig

@@ -54,6 +54,7 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_ACPI
 	select SOC_INTEL_COMMON_ACPI_WAKE_SOURCE
 	select SOC_INTEL_COMMON_BLOCK
+	select SOC_INTEL_COMMON_BLOCK_FAST_SPI
 	select SOC_INTEL_COMMON_BLOCK_ITSS
 	select SOC_INTEL_COMMON_BLOCK_LPSS
 	select SOC_INTEL_COMMON_BLOCK_PCR