Kconfig: memtest: update number of test patterns up to 17

Additional test patterns for memtest were introduced since commit
63823126 ("x86: memtest: add additional (regular) test patterns"),
but looks like Kconfig was not updated that time.

Update Kconfig entry with the actual number of maximum test patterns.

Change-Id: If94659077f7cbff544f8eff4fc80b1ccd8d90a41
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 8d8cfb47d67ef38f49f97fc0cd3cfe2b5dc8642e
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Venkatesh Yadav Abbarapu <vabbar@codeaurora.org>