Fix keypad mode and cursor mode

Keypad mode is used for detecting when keys in the auxiliary keypad are
pressed, while cursor mode is used for detecting when a cursor is pressed,
but they are different modes.

St was mixing both modes and DECPAM and DECPNM modified the cursor mode, and
this was incorrect.
---
 st.c    |    5 +++--
 st.info |    4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)