Revert "sm712fb_drv.c: set xpanstep and ypanstep"

This reverts commit e475557a8ec836105af6b5c0c14bd13446fecf26.
Revert "sm712fb_drv.c: add xpan and ypan flags."

This reverts commit 2a22bb4c7bae89622c2513931037f258854d2c1f.
sm712fb_drv.c: add FBINFO_READS_FAST flag.
lower freq for FB_BLANK_POWERDOWN, save the energy
Revert "lower freq for FB_BLANK_POWERDOWN, save the energy"

This reverts commit 6be25e5676d0fde835edfbacb4c9bac2375bc29c.