ARM: dts: am335x: Guardian: Update NAND partition table

 * Update partition table to save env and splash image
 * GPMC config values optimized for Bosch Guardian Board
 * NAND Chip used by Bosch Guardian Board is Micron MT29F4G08ABBFA

Signed-off-by: Gireesh Hiremath <Gireesh.Hiremath@in.bosch.com>
Message-Id: <20220325100613.1494-2-Gireesh.Hiremath@in.bosch.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>