ARM: OMAP2+: Drop hwmod data for am3 and am4 PRUSS

The PRUSS hwmod is currently not used in DT, and the new DTS
nodes shall be added using the ti-sysc infrastructure and the
omap-prm reset driver. Drop the legacy hwmod data for the
PRUSS module on both the AM33xx and AM437x family of SoCs.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>