OMAP2/3 GPTIMER: drop redundant pending write check

omap_dm_timer_write_reg() already waits for pending writes to complete,
so the extra wait in omap_dm_timer_set_load() is superfluous.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>