stm32mp: stm32prog: Add CONFIG_CMD_STM32PROG_SERIAL and _USB

Add CONFIG_CMD_STM32PROG_SERIAL and CONFIG_CMD_STM32PROG_USB to
independently select the support of UART or USB communication for
STM32CubeProgrammer.

For serial boot over UART, user can deactivate CONFIG_CMD_STM32PROG_SERIAL
to use U-Boot console of binary loaded by UART (for board bring-up for
example).

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/arch/arm/mach-stm32mp/Makefile b/arch/arm/mach-stm32mp/Makefile
index c8aa24d..aa39867 100644
--- a/arch/arm/mach-stm32mp/Makefile
+++ b/arch/arm/mach-stm32mp/Makefile
@@ -11,7 +11,7 @@
 ifdef CONFIG_SPL_BUILD
 obj-y += spl.o
 else
-obj-$(CONFIG_CMD_STM32PROG) += cmd_stm32prog/
+obj-y += cmd_stm32prog/
 obj-$(CONFIG_CMD_STM32KEY) += cmd_stm32key.o
 obj-$(CONFIG_ARMV7_PSCI) += psci.o
 obj-$(CONFIG_TFABOOT) += boot_params.o