lib: sbi_trap: Fix hstatus.SPVP update in sbi_trap_redirect()

When redirecting from VS/VU-mode to HS-mode, hstatus.SPVP was set
to the value of mstatus.SPP, as according to the specification both
flags should be set to the same value.
However, the assignment of SPVP takes place before SPP itself is
updated, which results in SPVP having an outdated value.

Signed-off-by: Georg Kotheimer <georg.kotheimer@tu-dresden.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>