MIPS: generic: Include asm/time.h for get_c0_*_int()

MIPS: generic: Include asm/time.h for get_c0_*_int()

arch/mips/generic/irq.c provides implementations of the
get_c0_compare_int() & get_c0_perfcount_int() functions, but doesn't
include the asm/time.h header which declares them. This leads to
warnings from sparse:

  arch/mips/generic/irq.c:36:5: warning: symbol 'get_c0_perfcount_int'
    was not declared. Should it be static?
  arch/mips/generic/irq.c:52:14: warning: symbol 'get_c0_compare_int'
    was not declared. Should it be static?

Fix this by including asm/time.h to get the declarations of
get_c0_compare_int() & get_c0_perfcount_int().

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17167/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>