lib: sbi_illegal_insn: Remove mcause, scratch and hartid parameters

We remove mcause, scratch and hartid parameters from various
functions for illegal instruction handling because we can always
get current HART id and current scratch pointer using just one
CSR access.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>