forked from Mirrors/opensbi

Writes to the low half CSR should not affect the high half of the value.
Make this separation explicit by writing to the delta in memory as two
adjacent XLEN-sized values.
Fixes: 1e9f88889f
("lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSR")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>