coco: virt: arm64: Do not enable cca guest driver by default

As per the guidelines, new drivers may not be set to default on.
An expert user can always select it.

Reported-by: Dan Williams <dan.j.williams@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Link: https://lore.kernel.org/r/6750c695194cd_2508129427@dwillia2-xfh.jf.intel.com.notmuch
Link: https://lore.kernel.org/r/20241205143634.306114-1-suzuki.poulose@arm.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: Suzuki K Poulose

drivers/virt/coco/arm-cca-guest/Kconfig

@@ -1,7 +1,6 @@
 config ARM_CCA_GUEST
 	tristate "Arm CCA Guest driver"
 	depends on ARM64
-	default m
 	select TSM_REPORTS
 	help
 	  The driver provides userspace interface to request and