ARM: stm32: Fix CONFIG_BOOTCOUNT_ALTBOOTCMD update on DH STM32MP1 DHSOM

The environment is missing closing quotes for string variable, but the
variable is empty on this system, remove the CONFIG_BOOTCOUNT_ALTBOOTCMD
assignment entirely.

Fixes: 940135eea5df ("Kconfig: Move CONFIG_BOOTCOUNT_ALTBOOTCMD to Kconfig")
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
3 files changed