ARM: OMAP2+: Fix potentially uninitialized return value for _setup_reset()

Commit 747834ab ("ARM: OMAP2+: hwmod: revise hardreset behavior") made
the call to _enable() conditional based on no oh->rst_lines_cnt. This
caused the return value to be potentially uninitialized. Curiously we see
no compiler warnings for this, probably as this gets inlined.

We call _setup_reset() from _setup() and only _setup_postsetup() if the
return value is zero. Currently the return value can be uninitialized for
cases where oh->rst_lines_cnt is set and HWMOD_INIT_NO_RESET is not set.

Fixes: 747834ab

 ("ARM: OMAP2+: hwmod: revise hardreset behavior")
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>