[RFC v2 19/24] powerpc: Remove CONFIG_GENERIC_NVRAM and adopt CONFIG_HAVE_ARCH_NVRAM_OPS

Switch PPC32 kernels from the generic_nvram module to the nvram module. Also fix a theoretical bug where CHRP omits the chrp_nvram_init() call when CONFIG_NVRAM_MODULE=m. As before, when CONFIG_PPC && !CONFIG_PPC_PMAC, the IOC_NVRAM_GET_OFFSET ioctl is unimplemented. For the nvram module,

[RFC v2 19/24] powerpc: Remove CONFIG_GENERIC_NVRAM and adopt CONFIG_HAVE_ARCH_NVRAM_OPS

Switch PPC32 kernels from the generic_nvram module to the nvram module. Also fix a theoretical bug where CHRP omits the chrp_nvram_init() call when CONFIG_NVRAM_MODULE=m. As before, when CONFIG_PPC !CONFIG_PPC_PMAC, the IOC_NVRAM_GET_OFFSET ioctl is unimplemented. For the nvram module,