forked from Mirrors/opensbi

We add optional fw_platform_init() function which will allow platform specific code to update "struct sbi_platform platform" before it is used. The fw_platform_init() can be a regular C function so before callint it we: 1. zero-out BSS section 2. Setup temporary trap handler to catch bugs 3. Setup temporary stack pointer Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>