ARM: OMAP2+: Fix missing SYSC_HAS_RESET_STATUS for dra7 epwmss

TRM says PWMSS_SYSCONFIG bit for SOFTRESET changes to zero when
reset is completed. Let's configure it as otherwise we get warnings
on boot when we check the data against dts provided data. Eventually
the legacy platform data will be just dropped, but let's fix the
warning first.

Reviewed-by: Suman Anna <s-anna@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>