misc: atmel: Remove CPU_AT32AP700X (AVR32) reference

The CPU_AT32AP700X symbol symbol went away when when AVR32 was removed
in commit 26202873 ("avr32: remove support for AVR32 architecture")

Remove the prompt from ATMEL_TCB_CLKSRC_BLOCK. The prompt condition
could never be satisfied now.

Discovered with the
https://github.com/ulfalizer/Kconfiglib/blob/master/examples/list_undefined.py
script.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/Kconfig

@@ -75,7 +75,6 @@ config ATMEL_TCB_CLKSRC
 config ATMEL_TCB_CLKSRC_BLOCK
 	int
 	depends on ATMEL_TCB_CLKSRC
-	prompt "TC Block" if CPU_AT32AP700X
 	default 0
 	range 0 1
 	help