generic: 5.15: Disable more config symbols

These came up while trying to build the lantiq target with Linux 5.15.

Signed-off-by: Martin Blumenstingl <[email protected]>

target/linux/generic/config-5.15

@@ -928,6 +928,7 @@ CONFIG_CIFS_XATTR=y
 # CONFIG_CLEANCACHE is not set
 # CONFIG_CLKSRC_PISTACHIO is not set
 # CONFIG_CLKSRC_VERSATILE is not set
+# CONFIG_CLKSRC_PISTACHIO is not set
 # CONFIG_CLK_GFM_LPASS_SM8250 is not set
 # CONFIG_CLK_HSDK is not set
 # CONFIG_CLK_QORIQ is not set