perf: imx_perf: add macro definitions for parsing config attr

The user can set event and counter in cmdline and the driver need to parse
it using 'config' attr value. This will add macro definitions to avoid
hard-code in driver.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240529080358.703784-2-xu.yang_2@nxp.com


Signed-off-by: Will Deacon <will@kernel.org>