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 <sjg@chromium.org>
Cc: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: York Sun <york.sun@nxp.com>
Cc: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Cc: Mingkai Hu <mingkai.hu@nxp.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Marek BehĂșn <marek.behun@nic.cz>
Cc: Vanessa Maegima <vanessa.maegima@nxp.com>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Adam Ford <aford173@gmail.com>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Tom Warren <twarren@nvidia.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/Makefile b/drivers/Makefile
index c425831..0538b50 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -53,8 +53,7 @@
 obj-$(CONFIG_SPL_USB_HOST_SUPPORT) += usb/host/
 obj-$(CONFIG_OMAP_USB_PHY) += usb/phy/
 obj-$(CONFIG_SPL_SATA_SUPPORT) += ata/ scsi/
-obj-$(CONFIG_SPL_USB_HOST_SUPPORT) += block/
-obj-$(CONFIG_SPL_MMC_SUPPORT) += block/
+obj-$(CONFIG_HAVE_BLOCK_DEVICE) += block/
 obj-$(CONFIG_SPL_FPGA_SUPPORT) += fpga/
 obj-$(CONFIG_SPL_THERMAL) += thermal/