bus: ti-sysc: remove set but not used variable 'quirks'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/bus/ti-sysc.c: In function sysc_reset:
drivers/bus/ti-sysc.c:1452:50: warning: variable quirks set but not used [-Wunused-but-set-variable]

It is never used since commit e0db94fe ("bus: ti-sysc: Make
OCP reset work for sysstatus and sysconfig reset bits")

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>