i2c-piix4: Remove the IMC detecting for Hygon SMBus

hygon inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8U3OJ


CVE: NA

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Remove IMC detecting path for Hygon processors.

Fixes: 24beb83a ("i2c-piix4: Add Hygon Dhyana SMBus support")
Signed-off-by: Pu Wen <puwen@hygon.cn>