Fix build for mips.XLP64 kernel, by re-ordering headers
The log for the failure contained errors like this:
| In file included from ${SRCTOP}/sys/mips/nlm/dev/net/xlpge.c:34: |
| In file included from ${SRCTOP}/sys/sys/systm.h:44: |
| In file included from ./machine/atomic.h:849: |
| ${SRCTOP}/sys/sys/_atomic_subword.h:222:37: error: unknown type name 'u_long'; did you mean 'long'? |
| atomic_testandset_acq_long(volatile u_long *p, u_int v) |
| ^~~~~~ |
| long |
And similar "unknown type name" errors for u_int, not recognizing bool as a type, etc.
This was caused by including <sys/param.h> too far down; move it up where it belongs.
While here, add a blank line after '__FBSDID()', in keeping with convention.
(cherry picked from commit 144af011b4ee87ed3eba4f2c9f6780f4543ba554)