reset: uniphier: enclose UNIPHIER_RESET_ID_END value in parentheses

Fixes a checkpatch error:

  ERROR: Macros with complex values should be enclosed in parentheses
  #23: FILE: drivers/reset/reset-uniphier.c:23:
  +#define UNIPHIER_RESET_ID_END		(unsigned int)(-1)

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>