checkpatch: update $allowed_asm_includes macros, add reboot.h and time.h

checkpatch: update $allowed_asm_includes macros, add reboot.h and time.h

Several architectures (e.g.  x86, MIPS, Blackfin) have asm/reboot.h and
asm/time.h header files, which are not included in linux/reboot.h and
linux/time.h headers.  This lead to generation of false positive errors.

Signed-off-by: Sergey Ryazanov <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Cc: Joe Perches <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>