Revert "cmake: Fix CPU architecture regexes"

This reverts commit 9c1dc4d13dab823d6441d417546ebeee3994389b.

The new regex for Intel can match "x86_64", but it fails with "x86".
Moreover, the new regex for MIPS needs more testing on all MIPS ISAs.

Reported-by: Clinton Ingram <clinton.ingram@outlook.com>
1 file changed