[3c90x] Clean up reset code

Remove duplicate hardware resets, remove network interface logic
reset.

This also fixes a bug where some 3c905C variants would return bogus
EEPROM values because of a too short delay after the network reset.

Signed-off-by: Thomas Miletich <thomas.miletich@gmail.com>
Reported-by: Peter Huewe <peterhuewe@gmx.de>
Tested-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/3c90x.h

@@ -193,6 +193,12 @@ enum Commands {
 	cmdSetHashFilterBit = 0x19,	/*                                   */
 };
 
+enum GlobalResetParams {
+	globalResetAll = 0,
+	globalResetMaskNetwork = (1<<2),
+	globalResetMaskAll = 0x1ff,
+};
+
 enum FrameStartHeader {
 	fshTxIndicate = 0x8000,
 	fshDnComplete = 0x10000,