clk: altera: n5x: Fix MEMCLKMGR_EXTCNTRST_C0CNTRST to bit(0)

MEMCLKMGR_EXTCNTRST_C0CNTRST register defined as BIT[0] in documentation
but it is wrongly defined as BIT[7] in u-boot code. This register is used
to hold associated pingpong counter in reset
while PLL and 5:1 mux configuration is changed.

Signed-off-by: Dinesh Maniyam <dinesh.maniyam@intel.com>
Reviewed-by: Tien Fong Chee <tien.fong.chee@intel.com>