arch: hexagon: kernel: hexagon_ksyms.c: export related symbols which various modules need

Need export all related functions and symbols for various modules with
allmodconfig. The related errors:

    MODPOST 2879 modules
  ERROR: "__vmyield" [sound/sound_firmware.ko] undefined!
  ERROR: "__phys_offset" [sound/drivers/snd-dummy.ko] undefined!
  ERROR: "ioremap_nocache" [drivers/char/ipmi/ipmi_si.ko] undefined!
  ERROR: "__iounmap" [drivers/char/ipmi/ipmi_si.ko] undefined!
  ...

For including files, need "linux/*" first, then "asm/*". All related
included files and symbols need be sorted by alphabetical order.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>