net: stmmac: Fix clock rate variables size

net: stmmac: Fix clock rate variables size

The clock API clk_get_rate() returns unsigned long value.
Expand affected members of stmmac platform data and
convert the stmmac_clk_csr_set() and dwmac4_core_init() methods
to defining the unsigned long clk_rate local variables.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jan Petrous (OSS) <jan.petrous@oss.nxp.com>
Link: https://patch.msgid.link/20241205-upstream_s32cc_gmac-v8-3-ec1d180df815@oss.nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>