lantiq: drop "CONFIG_HZ_100 is not set"

CONFIG_HZ_100 is not set to "y" in generic config anymore since
3a761c90af ("treewide: Don't diverge from upstream default HZ
settings on 4.19"), so we don't need to disable it anymore either.

This was the only remaining case in the entire tree.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/lantiq/config-4.19

@@ -110,7 +110,6 @@ CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN=y
 CONFIG_HW_HAS_PCI=y
 CONFIG_HW_RANDOM=y
 CONFIG_HZ=250
-# CONFIG_HZ_100 is not set
 CONFIG_HZ_250=y
 CONFIG_HZ_PERIODIC=y
 CONFIG_INITRAMFS_SOURCE=""

target/linux/lantiq/config-5.4

@@ -119,7 +119,6 @@ CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
 CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN=y
 CONFIG_HW_RANDOM=y
 CONFIG_HZ=250
-# CONFIG_HZ_100 is not set
 CONFIG_HZ_250=y
 CONFIG_HZ_PERIODIC=y
 CONFIG_INITRAMFS_SOURCE=""