ARM: dts: renesas: genmai: Fix partition size for QSPI NOR Flash

ARM: dts: renesas: genmai: Fix partition size for QSPI NOR Flash

Second partition was too large, looks like two digits got mixed up.
Fixes:

mtd: partition "user1" extends beyond the end of device "18000000.flash" -- size truncated to 0x4000000

Fixes: 30e0a8cf886c ("ARM: dts: renesas: genmai: Add FLASH nodes")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20240914182948.94031-2-wsa+renesas@sang-engineering.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>