[PARISC] OS_ID_LINUX == 0x0006

We were assigned an OS_ID of 0x0006. Consistently use OS_ID_LINUX
instead of using the magic number. Also update the OS_ID_ defines in
asm/pdc.h to reflect this.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
4 files changed