Updated formatting of geopm_pio_msr.7 page
Updated formatting of geopm_pio_msr.7 page

Updated formatting to be consistent with the rest of the chapter 7
documentation.

Signed-off-by: Alejandro Vilches <9dc86042069aa1c8b4fbbb563d12cc865d729cff@intel.com>

cmcantalupo/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,geopm/geopm,cmcantalupo/geopm