This will fix everything that uses a timer (or sleep).
Without this any function like eMMC/SD read/write/verify, TSEC/SE, etc can break when the time reaches the max value of the u32 microsecond timer (71minutes).
This fixes every possible breakage, including backup and restore (read/write/verify errors) that takes a lot of time.
The new max before a timer reset is now 48 days (the old one was 71 minutes)
- Sanitize framebuffer. Original idea from @StevenMattera
- Change clear framebuffer to memset (for grey colors), for performance (we don't use alpha blending, so it does not matter to set it to 0xFF).
- Enable screen backlight after gfx init
- Reduce wait time for emmc/sd read/write retries to 100ms.
