MIPS: BCM47xx: Move SPROM driver to drivers/firmware/

Broadcom ARM home routers store SPROM content in NVRAM just like MIPS
ones. To share SPROM code we need to move it out of arch/mips/ to some
common place. We already have bcm47xx_nvram in firmware path and SPROM
should fit there as well.
This driver is responsible for parsing SoC configuration data into a
struct shared between ssb and bcma buses.
This was tested with BCM4706 & BCM5357C0 (BCM47XX) and BCM4708A0
(ARCH_BCM_5301X).

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12210/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

drivers/firmware/broadcom/Kconfig

@@ -9,3 +9,14 @@ config BCM47XX_NVRAM
 	  This driver provides an easy way to get value of requested parameter.
 	  It simply reads content of NVRAM and parses it. It doesn't control any
 	  hardware part itself.
+
+config BCM47XX_SPROM
+	bool "Broadcom SPROM driver"
+	depends on BCM47XX_NVRAM
+	help
+	  Broadcom devices store configuration data in SPROM. Accessing it is
+	  specific to the bus host type, e.g. PCI(e) devices have it mapped in
+	  a PCI BAR.
+	  In case of SoC devices SPROM content is stored on a flash used by
+	  bootloader firmware CFE. This driver provides method to ssb and bcma
+	  drivers to read SPROM on SoC.

drivers/firmware/broadcom/Makefile

@@ -1 +1,2 @@
 obj-$(CONFIG_BCM47XX_NVRAM)		+= bcm47xx_nvram.o
+obj-$(CONFIG_BCM47XX_SPROM)		+= bcm47xx_sprom.o