ARM: OMAP2+: Remove calls to deprecacted marco,PTR_RET in the files,fb.c and pmu.c

This removes two calls to the deprecated marco,PTR_RET in
the files,fb.c and pmu.c for the functions,omap_init_vrfb
and omap_init_pmu respectfully. Furthermore these are now
replaced by calling the correctly non deprecacted function,
PTR_ERR_OR_ZERO in both functions.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>