KSP: change pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode) visibility

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>
KSP: change destination memory region from RX to RWX, and after patching back to RX

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>
KSP: added selftest

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>
KSP: fixed a typo ...

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>