apple_m1_defconfig: Turn on CONFIG_SYS_64BIT_LBA

This makes USB HDDs >2TiB work. The only reason this hasn't bitten us
for the internal NVMe yet is the 4K sector size, because the largest SSD
Apple sells is 8TB and we can handle up to 16TiB with that sector size.
Close call.

Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Janne Grunau <j@jannau.net>