MTD: remove obsolete Kconfig options

Remove the obsolete Kconfig options MTD_CFI_AMDSTD_RETRY
and MTD_CFI_AMDSTD_RETRY_MAX

The code that depended on these was removed in early 2004, but
Kconfig was not updated accordingly.

Signed-off-by: Anders Larsen <al@alarsen.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>