s390: remove unneeded 'select BUILD_BIN2C'

Since commit 4c0f032 ("s390/purgatory: Omit use of bin2c"),
s390 builds the purgatory without using bin2c.

Remove 'select BUILD_BIN2C' to avoid the unneeded build of bin2c.

Fixes: 4c0f032 ("s390/purgatory: Omit use of bin2c")
Signed-off-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexander Gordeev <[email protected]>

Author: masahir0y

arch/s390/Kconfig

@@ -484,7 +484,6 @@ config KEXEC
 config KEXEC_FILE
 	bool "kexec file based system call"
 	select KEXEC_CORE
-	select BUILD_BIN2C
 	depends on CRYPTO
 	depends on CRYPTO_SHA256
 	depends on CRYPTO_SHA256_S390