[otbn] Write flags on logical operations
[otbn] Write flags on logical operations

Previously logical operations did not alter flags, with this change the
M, L and Z flags are updated on all logical operations. C is left
unaltered.

Fixes #3688

Signed-off-by: Greg Chadwick <3e4c3d6d87c017d1a2fa161477653b4039c6b2fb@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan