blk: Rework guard around part_init call

blk: Rework guard around part_init call

The function part_init() will only be built when we have both
CONFIG_PARTITIONS and CONFIG_HAVE_BLOCK_DEVICE set.  Protect the call to
this function with both of these tests now.

Cc: Simon Glass <[email protected]>
Cc: Philipp Tomsich <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: York Sun <[email protected]>
Cc: Prabhakar Kushwaha <[email protected]>
Cc: Mingkai Hu <[email protected]>
Cc: Stefan Roese <[email protected]>
Cc: Marek Behún <[email protected]>
Cc: Vanessa Maegima <[email protected]>
Cc: Eugen Hristev <[email protected]>
Cc: Adam Ford <[email protected]>
Cc: Jagan Teki <[email protected]>
Cc: Tom Warren <[email protected]>
Cc: Stephen Warren <[email protected]>
Cc: Vitaly Andrianov <[email protected]>
Signed-off-by: Tom Rini <[email protected]>
Reviewed-by: Simon Glass <[email protected]>