nvmem: sort config symbols alphabetically

1. Match what most subsystems do
2. Simplify maintenance a bit
3. Reduce amount of conflicts for new drivers patches

While at it unify indent level in Makefile.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220916122100.170016-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>